summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/source/latex/changebar/changebar.dtx
blob: b0d01dbdf203219115f8694a9800196e5a6c1480 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
% \iffalse meta-comment
%
%% Copyright 1994-2018 (C) Johannes Braams.  All rights reserved.
%
% This file is part of the changebar package.
% -------------------------------------------
%
% It may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
%   http://www.latex-project.org/lppl.txt
% and version 1.3 or later is part of all distributions of LaTeX
% version 2003/12/01 or later.
%
% This work has the LPPL maintenance status "maintained".
%
% The Current Maintainer of this work is Johannes Braams.
%
% The list of all files belonging to the changebar package is
% given in the file `manifest.txt.
%
% The list of derived (unpacked) files belonging to the distribution
% and covered by LPPL is defined by the unpacking scripts (with
% extension .ins) which are part of the distribution.
% \fi
% \CheckSum{2579}
%
%\iffalse
%    This file is built for \LaTeXe, so we make sure an error is
%    generated when it is used with another format
%    \begin{macrocode}
%<+package>\NeedsTeXFormat{LaTeX2e}
%    \end{macrocode}
%
%    Now announce the package name and its version:
%    \begin{macrocode}
%<*dtx>
\ProvidesFile{changebar.dtx}
%</dtx>
%<+package>\ProvidesPackage{changebar}
           [2018/02/04 v3.6b Indicate changes with marginal bars]
%    \end{macrocode}
%
% \section{A driver for this document}
%
%    The next bit of code contains the documentation driver file for
%    \TeX{}, i.e., the file that will produce the documentation you
%    are currently reading. It will be extracted from this file by the
%    \textsc{docstrip} program.
%
%    \begin{macrocode}
%<*driver>
\documentclass{ltxdoc}
\usepackage[pdftex,rightbars,color]{changebar}
\cbcolor{red}
\DoNotIndex{\@@,\@Esphack,\@Mii,\@cons,\@empty,\@gobble}
\DoNotIndex{\@ifundefined,\@ne,\@spaces,\@whilenum}
\DoNotIndex{\advance,\begingroup,\bgroup,\egrou,\endgroup}
\DoNotIndex{\catcode,\chardef,\clearpage,\closein,\closeout}
\DoNotIndex{\csname,\endcsname,\def,\dimen@,\divide,\do,\dp}
\DoNotIndex{\edef,\expandafter}
\DoNotIndex{\gdef,\global}
\DoNotIndex{\GenericWarning,\hoffset,\ht}
\DoNotIndex{\ifcase,\or,\fi,\ifdim,\else,\fi,\ifeof,\fi,\ifnum,\fi}
\DoNotIndex{\ifvmode,\fi,\ifx,\fi,\ignorespaces,\immediate,\InputIfFileExists}
\DoNotIndex{\jobname,\let,\long,\m@ne,\maxdepth,\MessageBreak}
\DoNotIndex{\newcommand,\newcount,\newcounter,\newdimen,\newenvironment}
\DoNotIndex{\newlength,\newread,\newwrite,\next,\noexpand,\normalcolor}
\DoNotIndex{\openin,\openout,\OptionNotUsed,\p,\PacakgeError}
\DoNotIndex{\PackageWarning,\point,\ProcessOptions,\read,\relax}
\DoNotIndex{\RequirePackage,\setbox,\setcounter,\setlength,\space}
\DoNotIndex{\string,\strutbox,\t,\textwidth,\the,\thr@@,\tw@}
\DoNotIndex{\unvbox,\uppercase,\vadjust,\vbox,\vskip,\vss,\write,\xdef,\z@}
%    \end{macrocode}
%    We do want an index, using linenumbers
%    \begin{macrocode}
\EnableCrossrefs
\CodelineIndex
%    \end{macrocode}
%    This document uses some extra \texttt{doc} style macros.
%    \begin{macrocode}
\makeatletter
\def\DescribeVar#1{\leavevmode\@bsphack
    \marginpar{\raggedleft\PrintDescribeEnv{#1}}%
    \SpecialVarUsageIndex{#1}\@esphack\ignorespaces}
\def\SpecialVarMainIndex#1{\@bsphack
    \index{#1\actualchar\texttt{#1}\encapchar main}%
    \@esphack}
\def\SpecialVarUsageIndex#1{\@bsphack
    \index{#1\actualchar\texttt{#1}\encapchar usage}%
    \@esphack}
\let\@SpecialMainIndex\SpecialMainIndex
\def\Var{\let\SpecialMainIndex\SpecialVarMainIndex\macro}
\def\endVar{\endmacro\let\SpecialMainIndex\@SpecialMainIndex}
\makeatother
%    \end{macrocode}
%    Some commonly used abbreviations
%    \begin{macrocode}
\newcommand{\Lopt}[1]{\textsf {#1}}
\newcommand{\Lenv}[1]{\textsf {#1}}
\newcommand{\file}[1]{\texttt {#1}}
\newcommand{\pkg}[1]{\texttt {#1}}
\newcommand{\Lcount}[1]{\textsl {\small#1}}
\newcommand{\pstyle}[1]{\textsl {#1}}
%    \end{macrocode}
%    We also want the full details.
%    \begin{macrocode}
\begin{document}
\DocInput{changebar.dtx}
\end{document}
%</driver>
%    \end{macrocode}
%\fi
%
% \GetFileInfo{changebar.dtx}
%
% \changes{3.1}{1993/07/02}{Removed a number of typos}
% \changes{3.1a}{1993/08/03}{Uncommented \cs{filedate} and
%    \cs{fileversion}}
% \changes{3.2}{1994/04/21}{Incorporated Robin Fairbairns suggestions
%    for the upgrade for \LaTeX2e}
% \changes{3.2a}{1995/03/20}{Fixed bug about cross-page bars}
% \changes{v3.2b}{1995/06/26}{Removed use of \cs{file...} commands}
% \changes{v3.2b}{1995/06/26}{Use \LaTeX's Warning mechanisms}
% \changes{v3.2c}{1996/03/26}{Reinserted \cs{driver} for compatibility
%    reasons} 
% \changes{v3.4e}{2001/09/14}{Store original definitions using the
%    \texttt{ltx} prefix, define own versions with \texttt{cb} prefix,
%    the use \cmd{let} to replace \LaTeX\ macro.}
% \changes{v3.5a}{2005/05/23}{Piet van Oostrum: Resolved bugs in twocolumn
%    mode, mid-document changes to page number, added pdflatex support.}
% \changes{v3.6a}{2011/04/30}{Added support for XeTeX provided by
%    Apostolos Syropoulos}
% \changes{v3.6b}{2018/02/03}{Added a macro for pdf scaling for
%    Xe\TeX}
%
% \title{The Changebar package
%         \thanks{This file has version number \fileversion,
%                 last revised \filedate.}}
%
% \author{Michael Fine\\Distributed Systems Architecture \and
%         Johannes Braams\\
%         \texttt{texniek at braams.xs4all.nl}}
%
% \date{Printed \today}
%
% \maketitle
%
% \begin{multicols}{2}
%  \tableofcontents
% \end{multicols}
%
% \begin{abstract}
%    This package implements a way to indicate
%    modifications in a \LaTeX-document by putting bars in the
%    margin. It realizes this by making use of the |\special|
%    commands supported by `dvi drivers'. Currently six different
% \changes{v3.5a}{2005/05/23}{PDF\TeX{} support added}
% \changes{v3.6a}{2011/04/30}{Xe\TeX{} support added}
%    drivers are supported, plus pdftex\cbstart{} and XeTeX\cbend{}
%    support. More can easily be added. 
% \end{abstract}
%
% \section{Introduction}
%
%    \textbf{Important note} Just as with cross references and labels,
%    you usually need to process the document twice (and sometimes
%    three times) to ensure that the changebars come out
%    correctly. However, a warning will be given if another pass is
%    required. 
%
%    \textbf{Features}
%    \begin{itemize}
%    \item Changebars may be nested within each other.  Each level of
%    nesting can be given a different thickness bar. 
%
%    \item Changebars may be nested in other environments including
%    floats and footnotes.
%
%    \item Changebars are applied to all the material within the
%    ``barred'' environment, including floating bodies regardless of
%    where the floats float to.  An exception to this is margin
%    floats.
%
%    \item Changebars may cross page boundaries.
%
%    \item Changebars can appear on the \emph{outside} of the columns
%    of \Lopt{twocolumn} text.
%
%    \item The colour of the changebars can be changed. This has sofar
% \changes{v3.5a}{2005/05/23}{Pdftex support added}
% \changes{v3.6a}{2011/05/02}{xetex support added}
%      been tested with the \Lopt{dvips}, \Lopt{pdftex},
%      \Lopt{vtex} and\cbstart{}\Lopt{xetex}\cbend{} drivers, 
%      but it may also work with other PostScript based drivers. It will 
%      \emph{not} work for the \texttt{DVItoLN03} and em\TeX\ drivers.
%      For colored changebars to work, make sure that you specify the
% \changes{v3.5a}{2005/05/23}{Option xcolor mentioned}
%      option \Lopt{color} or \Lopt{xcolor}.
%    \end{itemize}
%
% \section{The user interface}
%
%    This package has options to specify some details of its
%    operation, and also defines several macros.
%
% \subsection{The package options}
% \subsubsection{Specifying the printer driver}
%
%    One set of package options\footnote{For older documents the
%    command \cs{driver} is available in the preamble of the document.
%    It takes the options as defined for \LaTeXe\ as argument.}
%    specify the driver that will be used to print the document can be
%    indicated. The driver may be one of: 
%    \begin{itemize}
%      \item DVItoLN03
%      \item DVItoPS
%      \item DVIps
%      \item em\TeX
%      \item \TeX tures
%      \item V\TeX
% \changes{v3.5a}{2005/05/23}{Pdftex support added}
%      \item PDF\TeX
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{XeTeX added}
%      \item Xe\TeX
% \end{changebar}
%    \end{itemize}
%    The drivers are represented in the normal typewriter method of
%    typing these names, or by the same entirely in lower case.
%    Since version 3.4d the driver can be specified in a configuration
%    file, not surprisingly called \file{changebar.cfg}. If it
%    contains the command |\ExecuteOption{textures}| the
%    \Lopt{textures} option will be used for all documents that are
%    processed while the configuration file is in \TeX's search path.
%
% \subsubsection{Specifying the bar position}
%    The position of the bars may either be on the inner edge of the
%    page (the left column on a recto or single-sided page, the right
%    column of a verso page) by use of the \Lopt{innerbars} package
%    option (the default), or on the outer edge of the page by use of
%    the \Lopt{outerbars} package option.
%
%    Another set of options gives the user the possibility of
%    specifying that the bars should \emph{always} come out on the
%    left side of the text (\Lopt{leftbars}) or on the right side of
%    the text (\Lopt{rightbars}). 
%
%    \emph{Note} that these options only work for \emph{onecolumn}
%    documents and will be ignored for a twocolumn document. 
%
% \subsubsection{Color}
%    For people who want their changebars to be colourfull the options
%    \Lopt{color} and \Lopt{xcolor} are available. They define the
%    user command |\cbcolor| and load either the \pkg{color} or the
%    \pkg{xcolor} package.
%
%    If a configuration file specifies the \Lopt{color} option and you
%    want to override it for a certain document you can use the
%    \Lopt{grey} option.
%
% \subsubsection{Tracing}
%    The package also implements tracing for its own debugging. The
%    package options \Lopt{traceon} and \Lopt{traceoff} control
%    tracing. An additional option \Lopt{tracestacks} is available for
%    the die hard who wants to know what goes on in the internal stacks
%    maintained by this package.
%
% \subsection{Macros defined by the package}
%
% \DescribeMacro{\cbstart}
% \DescribeMacro{\cbend}
%    All material between the macros |\cbstart| and |\cbend| is
%    barred.  The nesting of multiple changebars is allowed.  The
%    macro |\cbstart| has an optional parameter that specifies the
%    width of the bar. The syntax is |\cbstart[|\meta{dimension}|]|.
%    If no width is specified, the current value of the parameter
%    |\changebarwidth| is used.  Note that |\cbstart| and |\cbend| can
%    be used anywhere but must be correctly nested with floats and
%    footnotes.  That is, one cannot have one end of the bar inside a
%    floating insertion and the other outside, but that would be a
%    meaningless thing to do anyhow.
%
% \DescribeEnv{changebar}
%    Apart from the macros |\cbstart| and |\cbend| a proper \LaTeX\
%    environment is defined. The advantage of using the environment
%    whenever possible is that \LaTeX\ will do all the work of
%    checking the correct nesting of different environments.
%
% \DescribeMacro{\cbdelete}
%    The macro |\cbdelete| puts a square bar in the margin to indicate
%    that some text was removed from the document. The macro has an
%    optional argument to specify the width of the bar. When no
%    argument is specified the current value of the parameter
%    |\deletebarwidth| will be used.
%
% \DescribeMacro{\nochangebars}
%    The macro |\nochangebars| disables the changebar commands.
%
% \DescribeMacro{\cbcolor}
%    This macro is defined when the \Lopt{color} option is
%    selected. It's syntax is the same as the |\color| command from
%    the \pkg{color} package.
%
% \subsection{Changebar parameters}
%
% \DescribeMacro{\changebarwidth}
%    The width of the changebars is controlled with the \LaTeX\ length
%    parameter |\changebarwidth|.
%    Its value can be changed with the |\setlength| command.
%    Changing the value of |\changebarwidth| affects all subsequent
%    changebars subject to the scoping rules of |\setlength|.
%
% \DescribeMacro{\deletebarwidth}
%    The width of the deletebars is controlled with the \LaTeX\ length
%    parameter |\deletebarwidth|.
%    Its value can be changed with the |\setlength| command.
%    Changing the value of |\deletebarwidth| affects all subsequent
%    deletebars subject to the scoping rules of |\setlength|.
%
% \DescribeMacro{\changebarsep}
%    The separation between the text and the changebars is determined
%    by the value of the \LaTeX\ length parameter |\changebarsep|.
%
% \DescribeVar{changebargrey}
%    When one of the supported dvi to PostScript translators is used
%    the `blackness' of the bars can be controlled. The \LaTeX\
%    counter \texttt{changebargrey} is used for this purpose. Its
%    value can be changed with a command like:
%    \begin{verbatim}
%    \setcounter{changebargrey}{85}
%    \end{verbatim}
%    The value of the counter is a percentage, where the value 0 yields
%    black bars, the value 100 yields white bars.
%
% \DescribeVar{outerbars}
%    The changebars will be printed in the `inside' margin of your
%    document.  This means they appear on the left side of the
%    page. When \Lopt{twoside} is in effect the bars will be printed
%    on the right side of even pages.  \cbdelete
%
%
% \section{Deficiencies and bugs}
%
% \begin{itemize}
% \item The macros blindly use special points |\cb@minpoint| through
%    |\cb@maxpoint|. If this conflicts with another set of macros, the
%    results will be unpredictable.  (What is really needed is a
%    |\newspecialpoint|, analogous to |\newcount| etc.~--- it's not
%    provided because the use of the points is rather rare.)
%
% \item There is a limit of 
%    $(\mbox{\texttt{\bslash cb@maxpoint}}-
%    \mbox{\texttt{\bslash cb@minpoint}}+1)/4$ bars per page
%    (four special points per bar).  Using more than this number yields
%    unpredictable results (but that could be called a feature for a
%    page with so many bars).  This limitation could be increased if
%    desired.
% \changes{v3.5a}{2005/05/23}{Pdftex support added}
% \changes{v3.6a}{2011/04/30}{XeTeX suport added}
%    There is no such limit with PDF\TeX \cbstart or Xe\TeX\cbend.
%
% \item Internal macro names are all of the form |\cb@xxxx|.  No
%    checking for conflicts with other macros is done.
%
% \item This implementation does not work with the
%    \texttt{multicolumn} package.
%
% \item The algorithms may fail if a floating insertion is split over
%    multiple pages.  In \LaTeX\ floats are not split but footnotes
%    may be.  The simplest fix to this is to prevent footnotes from
%    being split but this may make \TeX\ very unhappy.
%
% \item The |\cbend| normally gets ``attached'' to the token after it
%    rather than the one before it.  This may lead to a longer bar
%    than intended.  For example, consider the sequence `word1
%    |\cbend| word2'.  If there is a line break between `word1' and
%    `word2' the bar will incorrectly be extended an extra line.  This
%    particular case can be fixed with the incantation
%    `word1|\cbend{}| word2'.
%
% \item The colour support has only been tested with the \Lopt{dvips}
% \changes{v3.5a}{2005/05/23}{Pdftex support added}
%    and \Lopt{pdftex} drivers. 
%  \end{itemize}
%
% \section{The basic algorithm}
%
%    The changebars are implemented using the |\specials| of various
%    \texttt{dvi} interpreting programs like \texttt{DVItoLN03} or
%    \texttt{DVIps}.  In essence, the start of a changebar defines two
%    |\special| points in the margins at the current vertical position
%    on the page.  The end of a changebar defines another set of two
%    points and then joins (using the ``connect'' |\special|) either
%    the two points to the left or the two points to the right of the
%    text, depending on the setting of \Lopt{innerbars},
%    \Lopt{outerbars}, \Lopt{leftbars}, \Lopt{rightbars} and/or
%    \Lopt{twoside}. 
%
%    This works fine as long as the two points being connected lie on
%    the same page.  However, if they don't, the bar must be
%    artificially terminated at the page break and restarted at the
%    top of the next page.  The only way to do this (that I can think
%    of) is to modify the output routine so that it checks if any bar
%    is in progress when it ships out a page and, if so, adds the
%    necessary artificial end and begin.
%
%    The obvious way to indicate to the output routine that a bar is
%    in progress is to set a flag when the bar is begun and to unset
%    this flag when the bar is ended.  This works most of the time
%    but, because of the asynchronous behavior of the output routine,
%    errors occur if the bar begins or ends near a page break.  To
%    illustrate, consider the following scenario.
%
%    \begin{verbatim}
%    blah blah blah          % page n
%    blah blah blah
%    \cbstart                % this does its thing and set the flag
%    more blah
%               <-------------- pagebreak occurs here
%    more blah
%    \cbend                  % does its thing and unsets flag
%    blah blah
%    \end{verbatim}
%
%    Since \TeX\ processes ahead of the page break before invoking the
%    output routine, it is possible that the |\cbend| is
%    processed, and the flag unset, before the output routine is
%    called.  If this happens, special action is required to generate
%    an artificial end and begin to be added to page $n$ and $n+1$
%    respectively, as it is not possible to use a flag to signal
%    the output routine that a bar crosses a page break.
%
%    The method used by these macros is to create a stack of the
%    beginning and end points of each bar in the document together
%    with the page number corresponding to each point.  Then, as a
%    page is completed, a modified output routine checks the stack to
%    determine if any bars begun on or before the current page are
%    terminated on subsequent pages, and handles those bars
%    appropriately.  To build the stack, information about each
%    changebar is written to the \file{.aux} file as bars are processed.
%    This information is re-read when the document is next processed.
%    Thus, to ensure that changebars are correct, the document must
%    be processed twice.  Luckily, this is generally required for
%    \LaTeX\ anyway. 
%    With PDF\LaTeX{} generally three (or even more) runs
%    are necessary.
%
%    This approach is sufficiently general to allow nested bars, bars
%    in floating insertions, and bars around floating insertions.
%    Bars inside floats and footnotes are handled in the same way as
%    bars in regular text.  Bars that encompass floats or footnotes
%    are handled by creating an additional bar that floats with the
%    floating material.  Modifications to the appropriate \LaTeX\
%    macros check for this condition and add the extra bar.
%
%\StopEventually{
% \IndexPrologue{\section*{Index}%
%  \markboth{Index}{Index}%
%     Numbers in \emph{italics} indicate the page where the
%     macro is described, the underlined numbers indicate
%     the number of the line of code where the macro is defined,
%     all other numbers indicate where a macro is used.}
%
% \GlossaryPrologue{\section*{History of changes}%
%    \markboth{History of changes}{History of changes}%
%    The numbers behind the changes indicate the page where
%    the macrocode is described.\hfil\null}
%
%  \PrintIndex
%^^AA \PrintChanges
% }
% \section{The implementation}
%
% \subsection{Declarations And Initializations}
%
% \begin{macro}{\cb@maxpoint}
%    The original version of \texttt{changebar.sty} only supported the
%    \texttt{DVItoLN03} specials. The \texttt{LN03} printer has a
%    maximum number of points that can be defined on a page. Also for
%    some PostScript printers the number of points that can be defined
%    can be limited by the amount of memory used. Therefore, the
%    consecutive numbering of points has to be reset when the maximum
%    is reached. This maximum can be adapted to the printers needs.
%    \begin{macrocode}
%<*package>
\def\cb@maxpoint{80}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@minpoint}
%    When resetting the point number we need to know what to reset it
%    to, this is minimum number is stored in |\cb@minpoint|.
%    \textbf{This number has to be \emph{odd}} because the algorithm
%    that decides whether a bar has to be continued on the next page
%    depends on this.
%    \begin{macrocode}
\def\cb@minpoint{1}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@nil}
%    Sometimes a void value for a point has to be returned by one
%    of the macros. For this purpose |\cb@nil| is used.
%    \begin{macrocode}
\def\cb@nil{0}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@nextpoint}
%    The number of the next special point is stored in the count
%    register |\cb@nextpoint| and initially equal to
%    |\cb@minpoint|.
%    \begin{macrocode}
\newcount\cb@nextpoint
\cb@nextpoint=\cb@minpoint
%    \end{macrocode}
% \end{macro}
%
%  \begin{macro}{\cb@topleft}
% \changes{v3.3a}{1997/09/26}{Renamed \cs{cb@currentpoint} to
%    \cs{cb@topleft}}
%  \begin{macro}{\cb@topright}
% \changes{v3.3a}{1997/09/26}{New counter}
%  \begin{macro}{\cb@botleft}
% \changes{v3.3a}{1997/09/26}{New counter}
%  \begin{macro}{\cb@botright}
% \changes{v3.3a}{1997/09/26}{New counter}
%    These four counters are used to identify the four special points
%    that specify a changebar. The point defined by |\cb@topleft| is
%    the one used to identify the changebar; the values of the other
%    points are derived from it.
%    \begin{macrocode}
\newcount\cb@topleft
\newcount\cb@topright
\newcount\cb@botleft
\newcount\cb@botright
%    \end{macrocode}
%  \end{macro}
%  \end{macro}
%  \end{macro}
%  \end{macro}
%
%  \begin{macro}{\cb@cnta}
% \changes{v3.4f}{2003/10/18}{New temporary storage counter, replaces
%    the use of \cs{@tempcnta}}
%  \begin{macro}{\cb@cntb}
% \changes{v3.4f}{2003/10/18}{New temporary storage counter, replaces
%    the use of \cs{@tempcntb}}
%  \begin{macro}{\cb@dima}
% \changes{v3.4f}{2003/10/18}{New temporary storage dimension}
%    Sometimes we need temporarily store a value. For this purpose two
%    count registers and a dimension register are allocated.
%    \begin{macrocode}
\newcount\cb@cnta
\newcount\cb@cntb
\newdimen\cb@dima
%    \end{macrocode}
%  \end{macro}
%  \end{macro}
%  \end{macro}
%
%  \begin{macro}{\cb@curbarwd}
% \changes{v3.3a}{1997/09/26}{Introduced \cs{curbarwd} to eliminate
%    the use of \cs{@tempdima}} 
%    The dimension register |\cb@curbarwd| is used to store the width of
%    the current bar.
%    \begin{macrocode}
\newdimen\cb@curbarwd
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\cb@page}
% \begin{macro}{\cb@pagecount}
% \changes{v3.5a}{2005/05/23}{Twocolumn support changes}
%    The macros need to keep track of the number of pages/columns
%    output so far.  To this end the counter |\cb@pagecount| is used.
%    When a pagenumber is read from the history stack, it is stored in
%    the counter |\cb@page|. The counter |\cb@pagecount| is initially
%    $0$; it gets incremented during the call to |\@makebox| (see
%    section~\ref{pagebreak}).
%    \begin{macrocode}
\newcount\cb@page
\newcount\cb@pagecount
\cb@pagecount=0
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\cb@barsplace}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    A switch is provided to control where the changebars will be
%    printed. 
%    The value depends on the options given:
%    \begin{itemize}
%    \item[0] for innerbars (default),
%    \item[1] for outerbars,
%    \item[2] gives leftbars,
%    \item[3] gives rightbars.
%    \end{itemize}
%    \begin{macrocode}
\def\cb@barsplace{0}
%    \end{macrocode}
% \end{macro}
%
%  \begin{Var}{@cb@trace}
%    A switch to enable tracing of the actions of this package.
%    \begin{macrocode}
\newif\if@cb@trace
%    \end{macrocode}
%  \end{Var}
%
%  \begin{Var}{@cb@firstcolumn}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    A switch to find out if a point is in the left column of a
%    twocolumn page. 
%    \begin{macrocode}
\newif\if@cb@firstcolumn
%    \end{macrocode}
%  \end{Var}
%
% \begin{macro}{\cb@pdfxy}
% \changes{v3.5a}{2005/05/23}{Pdftex support added}
%    The macro |\cb@pdfxy| populates the pdf x,y coordinates file.
%    In \Lopt{pdftex}\cbstart{} and \Lopt{xetex}\cbend{} mode it
%    writes one line to \file{.cb2} file
%    which is equivalent to one bar point. The default implementation
%    is a noop. 
%    If the \Lopt{pdftex}\cbstart{} or \Lopt{xetex}\cbend{} option is
%    given it is redefined.
%    \begin{macrocode}
\def\cb@pdfxy#1#2#3#4#5{}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@positions}
%
%    This macro calculates the (horizontal) positions of the
%    changebars.  
%
%  \begin{macro}{\cb@odd@left}
% \changes{v3.3a}{1997/09/26}{Renamed from \cs{b@odd}}
%  \begin{macro}{\cb@odd@right}
% \changes{v3.3a}{1997/09/26}{New dimension register}
%  \begin{macro}{\cb@even@left}
% \changes{v3.3a}{1997/09/26}{Renamed from \cs{b@even}}
%  \begin{macro}{\cb@even@right}
% \changes{v3.3a}{1997/09/26}{New dimension register}
%    Because the margins can differ for even and odd pages and because
%    changebars are sometimes on different sides of the paper we need
%    four dimensions to store the result.
%
%    \begin{macrocode}
\newdimen\cb@odd@left
\newdimen\cb@odd@right
\newdimen\cb@even@left
\newdimen\cb@even@right
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
%    Since the changebars are drawn with the \textsc{PostScript}
%    command \texttt{lineto} and not as \TeX{}-like rules the
%    reference points lie on the center of the changebar, therefore
%    the calculation has to add or subtract half of the width of the
%    bar to keep |\changebarsep| whitespace between the bar and the
%    body text.
%
%    First the position for odd pages is calculated.
% \changes{v3.1}{1993/07/02}{Corrected positioning of PostScript bars}
% \changes{v3.3a}{1997/09/26}{calculate horizontal positions
%    independent of options used}
% \changes{v3.3d}{1997/10/28}{Removed bogus offset}
% \changes{v3.3g}{1999/06/11}{Don't use \cs{evensidemargin} when
%    \Lopt{twoside} is \emph{not} in effect}
%    \begin{macrocode}
\def\cb@positions{%
  \global\cb@odd@left=\hoffset
  \global\cb@even@left\cb@odd@left
  \global\advance\cb@odd@left by \oddsidemargin
  \global\cb@odd@right\cb@odd@left
  \global\advance\cb@odd@right by \textwidth
  \global\advance\cb@odd@right by \changebarsep
  \global\advance\cb@odd@right by 0.5\changebarwidth
  \global\advance\cb@odd@left by -\changebarsep
  \global\advance\cb@odd@left by -0.5\changebarwidth
%    \end{macrocode}
%    On even sided pages we need to use |\evensidemargin| in the
%    calculations when \Lopt{twoside} is in effect. 
%    \begin{macrocode}
  \if@twoside
    \global\advance\cb@even@left by \evensidemargin
    \global\cb@even@right\cb@even@left
    \global\advance\cb@even@left by -\changebarsep
    \global\advance\cb@even@left by -0.5\changebarwidth
    \global\advance\cb@even@right by \textwidth
    \global\advance\cb@even@right by \changebarsep
    \global\advance\cb@even@right by 0.5\changebarwidth
  \else
%    \end{macrocode}
%    Otherwise just copy the result for odd pages.
%    \begin{macrocode}
    \global\let\cb@even@left\cb@odd@left
    \global\let\cb@even@right\cb@odd@right
  \fi
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@removedim}
%    In PostScript code, length specifications are without dimensions.
%    Therefore we need a way to remove the letters `pt' from the
%    result of the operation |\the\|\meta{dimen}.
%    This can be done by defining a command that has a delimited
%    argument like:
%    \begin{verbatim}
%    \def\cb@removedim#1pt{#1}
%    \end{verbatim}
%    We encounter one problem though, the category code of the letters
%    `pt' is 12 when produced as the output from |\the\|\meta{dimen}.
%    Thus the characters that delimit the argument of |\cb@removedim|
%    also have to have category code 12. To keep the changes local
%    the macro |\cb@removedim| is defined in a group.
%    \begin{macrocode}
{\catcode`\p=12\catcode`\t=12 \gdef\cb@removedim#1pt{#1}}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Option Processing}
%
%    The user should select the specials that should be used by
%    specifying the driver name as an option to the
%    |\usepackage| call.
% \changes{v3.5a}{2005/05/23}{Added the option \Lopt{PDFTeX}}
% \changes{v3.6a}{2011/04/30}{Added the option \Lopt{XeTeX}}
%    Possible choices are:
%    \begin{itemize}
%    \item DVItoLN03
%    \item DVItoPS
%    \item DVIps
%    \item em\TeX
%    \item Textures
%    \item V\TeX
%    \item PDF\TeX
% \begin{changebar}
%    \item Xe\TeX
% \end{changebar}
%    \end{itemize}
%
%    The intent is that the driver names should be case-insensitive,
%    but the following code doesn't achieve this: it only permits the
%    forms given above and their lower-case equivalents.
% \changes{v3.3e}{1998/02/24}{Added the option \Lopt{textures}}
% \changes{v3.4a}{2001/04/18}{Added the option \Lopt{VTeX}}
% \changes{v3.5a}{2005/05/23}{Added the option \Lopt{PDFTeX}}
% \changes{v3.6a}{2011/04/30}{Added the option \Lopt{XeTeX}}
%    \begin{macrocode}
\DeclareOption{DVItoLN03}{\global\chardef\cb@driver@setup=0\relax}
\DeclareOption{dvitoln03}{\global\chardef\cb@driver@setup=0\relax}
\DeclareOption{DVItoPS}{\global\chardef\cb@driver@setup=1\relax}
\DeclareOption{dvitops}{\global\chardef\cb@driver@setup=1\relax}
\DeclareOption{DVIps}{\global\chardef\cb@driver@setup=2\relax}
\DeclareOption{dvips}{\global\chardef\cb@driver@setup=2\relax}
\DeclareOption{emTeX}{\global\chardef\cb@driver@setup=3\relax}
\DeclareOption{emtex}{\global\chardef\cb@driver@setup=3\relax}
\DeclareOption{textures}{\global\chardef\cb@driver@setup=4\relax}
\DeclareOption{Textures}{\global\chardef\cb@driver@setup=4\relax}
\DeclareOption{VTeX}{\global\chardef\cb@driver@setup=5\relax}
\DeclareOption{vtex}{\global\chardef\cb@driver@setup=5\relax}
%    \end{macrocode}
%    \begin{macrocode}
\DeclareOption{PDFTeX}{\cb@pdftexcheck}
\DeclareOption{pdftex}{\cb@pdftexcheck}
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{PDFTeX support added}
%    For the \Lopt{pdftex} option we have to check that the current
%    \LaTeX{} run is using PDF\TeX{} and that PDF output is selected.
%    If it is, we initialize the option and open an additional output file.
%    If not, we ignore the option and issue a warning.
%    \begin{macrocode}
\def\cb@pdftexcheck{%
  \ifx\pdfsavepos\@undefined\cb@pdftexerror
  \else\ifx\pdfoutput\@undefined\cb@pdftexerror
  \else\ifnum\pdfoutput>0
    \global\chardef\cb@driver@setup=6\relax
    \ifx\cb@writexy\@undefined
      \newwrite\cb@writexy
      \newread\cb@readxy
      \immediate\openout\cb@writexy=\jobname.cb2\relax
    \fi
%    \end{macrocode}
%    Redefine the |\cb@pdfxy| macro to write point coordinates to the
%    \file{.cb2} file.
%    \begin{macrocode}
    \gdef\cb@pdfxy##1##2##3##4##5{%
      \immediate\write\cb@writexy{##1.##2p##3,##4,##5}%
      \expandafter\gdef\csname cb@##1.##2\endcsname{##3,##4,##5}}
  \else\cb@pdftexerror\fi\fi\fi}
%    \end{macrocode}
%    Give a warning if we cannot support the \Lopt{pdftex} option.
%    \begin{macrocode}
\def\cb@pdftexerror{\PackageError
      {changebar}%
      {PDFTeX option cannot be used}%
      {You are using a LaTeX run which does not generate PDF\MessageBreak
        or you are using a very old version of PDFTeX}}
%    \end{macrocode}
%\clearpage
% \begin{changebar}
%    \begin{macrocode}
\DeclareOption{XeTeX}{\cb@xetexcheck}
\DeclareOption{xetex}{\cb@xetexcheck}
%    \end{macrocode}
% \changes{v3.6a}{2005/05/23}{XeTeX support added}
%    For the \Lopt{xetex} option we have to check that the current
%    \LaTeX{} run is using Xe\TeX{}.
%    If it is, we initialize the option and open an additional output file.
%    If not, we ignore the option and issue a warning..
%    \begin{macrocode}
\def\cb@xetexcheck{%
  \expandafter\ifx\csname XeTeXrevision\endcsname\@undefined \cb@xetexerror
  \else
    \global\chardef\cb@driver@setup=7\relax
    \ifx\cb@writexy\@undefined
      \newwrite\cb@writexy
      \newread\cb@readxy
      \immediate\openout\cb@writexy=\jobname.cb2\relax
    \fi
%    \end{macrocode}
%    Redefine the |\cb@pdfxy| macro to write point coordinates to the
%    \file{.cb2} file.
%    \begin{macrocode}
    \gdef\cb@pdfxy##1##2##3##4##5{%
      \immediate\write\cb@writexy{##1.##2p##3,##4,##5}%
      \expandafter\gdef\csname cb@##1.##2\endcsname{##3,##4,##5}}
    \gdef\sec@nd@ftw@##1 ##2{##2}
  \fi}
%    \end{macrocode}
%
%    Give a warning if we cannot support the \Lopt{xetex} option.
%    \begin{macrocode}
\def\cb@xetexerror{\PackageError
      {changebar}%
      {XeTeX option cannot be used}%
      {You are not using XeLaTeX}}
%    \end{macrocode}
% \end{changebar}
%
%    The new features of \LaTeXe\ make it possible to implement the
%    \Lopt{outerbars} option.
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    \begin{macrocode}
\DeclareOption{outerbars}{\def\cb@barsplace{1}}
\DeclareOption{innerbars}{\def\cb@barsplace{0}}
%    \end{macrocode}
%
%    It is also possible to specify that the change bars should
%    \emph{always} be printed on either the left or the right side of
%    the text. For this we have the options \Lopt{leftbars} and
%    \Lopt{rightbars}. Specifying \emph{either} of these options will
%    overrule a possible \Lopt{twoside} option at the document level.
% \changes{v3.2b}{1995/06/27}{Added the options\Lopt{leftbars} and
%    \Lopt{rightbars}}
% \changes{v3.3d}{1997/10/28}{Removed bogus offset}
% \changes{v3.3g}{1999/06/11}{take the setting of \Lopt{twoside} into
%    account}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    \begin{macrocode}
\DeclareOption{leftbars}{\def\cb@barsplace{2}}
\DeclareOption{rightbars}{\def\cb@barsplace{3}}
%    \end{macrocode}
% \changes{v3.3j}{2000/09/26}{\cs{cb@even@right} erroneously wasn't
%    set in the oneside mode with option rightbars}
%    A set of options to control tracing.
% \changes{v3.4b}{2001/08/27}{Added tracing of push and pop
%    operations}
%    \begin{macrocode}
\DeclareOption{traceon}{\@cb@tracetrue}
\DeclareOption{traceoff}{\@cb@tracefalse}
\DeclareOption{tracestacks}{%
  \let\cb@trace@stack\cb@@show@stack
  \def\cb@trace@push#1{\cb@trace{%
      Pushed point \the\cb@topleft\space on \noexpand#1: #1}}%
  \def\cb@trace@pop#1{\cb@trace{%
      Popped point \the\cb@topleft\space from \noexpand#1: #1}}%
  }
%    \end{macrocode}
%    Three options are introduced for colour support. The first one,
%    \Lopt{grey}, is activated by default.
% \changes{v3.4b}{2001/08/28}{Added options \Lopt{grey} and
%    \Lopt{color}}
%    \begin{macrocode}
\DeclareOption{grey}{%
  \def\cb@ps@color{\thechangebargrey\space 100 div setgray}}
%    \end{macrocode}
%    The second option activates support for the \pkg{color} package.
%    \begin{macrocode}
\DeclareOption{color}{%
  \def\cb@ps@color{\expandafter\c@lor@to@ps\cb@current@color\@@}%
  \def\cb@color@pkg{color}}
%    \end{macrocode}
%    The third option adds support for the \pkg{xcolor} package.
% \changes{v3.4h}{2004/08/26}{Added option \Lopt{xcolor} to support
%    the \pkg{xcolor} package}
%    \begin{macrocode}
\DeclareOption{xcolor}{%
  \def\cb@ps@color{\expandafter\c@lor@to@ps\cb@current@color\@@}%
  \def\cb@color@pkg{xcolor}}
%    \end{macrocode}
%
%    Signal an error if an unknown option was specified.
% \changes{v3.5a}{2005/05/23}{Added 'pdftex' to the option list}
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{Added 'xetex' to the option list}
%    \begin{macrocode}
\DeclareOption*{\OptionNotUsed\PackageError
      {changebar}%
      {Unrecognised option `\CurrentOption'\MessageBreak
        known options are dvitoln03, dvitops, dvips,\MessageBreak
        emtex, textures, pdftex, vtex and xetex, 
        grey, color, xcolor,\MessageBreak
        outerbars, innerbars, leftbars and rightbars}}
%    \end{macrocode}
% \end{changebar}
%
%    The default is to have grey change bars on the left side of the
%    text on odd pages. When V\TeX\ is used the option \Lopt{dvips} is
%    not the right one, so in that case we have \Lopt{vtex} as the
%    default driver.
%    When PDF\TeX{} is producing PDF output, the \Lopt{pdftex} option is
%    selected. 
% \changes{v3.2c}{1996/03/26}{Added `dvips' to the list of default
%    options} 
% \changes{v3.4b}{2001/08/28}{Added `grey' to the list of default
%    options}
% \changes{v3.4d}{2001/09/04}{Added detection of V\TeX}
% \changes{v3.5a}{2005/05/23}{Added detection of PDF\TeX}
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{Added detection of Xe\TeX}
%    \begin{macrocode}
\ifx\VTeXversion\@undefined
  \expandafter\ifx\csname XeTeXrevision\endcsname\@undefined
    \ifx\pdfoutput\@undefined
      \ExecuteOptions{innerbars,traceoff,dvips,grey}
    \else
      \ifnum\pdfoutput>0
        \ExecuteOptions{innerbars,traceoff,pdftex,grey}
      \else
        \ExecuteOptions{innerbars,traceoff,dvips,grey}
      \fi
    \fi
  \else
    \ExecuteOptions{innerbars,traceoff,xetex,grey}
  \fi
\else
  \ExecuteOptions{innerbars,traceoff,vtex,grey}
\fi
%    \end{macrocode}
% \end{changebar}
%
%    A local configuration file may be used to define a site wide
%    default for the driver, by calling |\ExecuteOptions| with the
%    appropriate option. This will override the default specified
%    above.
% \changes{v3.4d}{2001/09/04}{Added the possibility of loading a
%    configuration file}
%    \begin{macrocode}
\InputIfFileExists{changebar.cfg}{}{}
%    \end{macrocode}
%
%  \begin{macro}{\cb@@show@stack}
% \changes{v3.3g}{1999/06/11}{Macro added}
%    When the stack tracing facility is turned on this command is
%    executed. It needs to be defined \emph{before} we call
%    |\ProcessOptions|. This command shows the contents of the stack
%    with currently `open' bars, the stack with pending ends and the
%    history stack. It does \emph{not} show the temporary stack.
% \changes{v3.3h}{1999/06/15}{Added the historystack to the stack
%    tracing}
%    \begin{macrocode}
\def\cb@@show@stack#1{%
  \cb@trace{%
    stack status at #1:\MessageBreak
    current stack: \cb@currentstack\MessageBreak
    \@spaces end stack: \cb@endstack\MessageBreak
    \space\space begin stack: \cb@beginstack\MessageBreak
    history stack: \cb@historystack 
    }}
%    \end{macrocode}
%    The default is to \emph{not} trace the stacks. This is achieved by
%    |\let|ting |\cb@trace@stack| to |\@gobble|.
%    \begin{macrocode}
\let\cb@trace@stack\@gobble
%    \end{macrocode}
%  \end{macro}
%
%  \begin{macro}{\cb@trace@push}
%  \begin{macro}{\cb@trace@pop}
% \changes{v3.4b}{2001/08/27}{Added macros for tracing stack push and
%    pop operations} 
%    When stack tracing is turned on, these macros are used to display
%    the push and pop operations that go on. They are defined when the 
%    package option \Lopt{tracestacks} is selected.
%
%    The default is to \emph{not} trace the stacks. 
%    \begin{macrocode}
\let\cb@trace@push\@gobble
\let\cb@trace@pop\@gobble
%    \end{macrocode}
%  \end{macro}
%  \end{macro}
%
%    Now make all the selected options active, but...
%    \begin{macrocode}
\ProcessOptions\relax
%    \end{macrocode}
%
%    We have to make sure that when the document is being processed by
%    pdf\LaTeX, while also creating pdf as output, the driver to be
%    used is the pdf driver. Therefore we add an extra check, possibly
%    overriding a \Lopt{dvips} option that might still have been in
%    the doucment.
% \changes{v3.5b}{2005/05/31}{Added an extra check for pdftex in pdf
%    mode}
%    \begin{macrocode}
\ifx\pdfsavepos\@undefined
\else
  \ifx\pdfoutput\@undefined
  \else
    \ifnum\pdfoutput>0
      \global\chardef\cb@driver@setup=6\relax
    \fi
  \fi
\fi
%    \end{macrocode}
%
%  \begin{macro}{\cb@trace}
%    A macro that formats the tracing messages.
% \changes{v3.3g}{1999/06/11}{removed line number from tracing
%    messages}
%    \begin{macrocode}
\newcommand{\cb@trace}[1]{%
  \if@cb@trace
    \GenericWarning
      {(changebar)\@spaces\@spaces}%
      {Package changebar: #1\@gobble}%
  \fi
  }
%    \end{macrocode}
%  \end{macro}
%
% \subsection{User Level Commands And Parameters}
%
% \begin{macro}{\driver}
%    The user can select the specials that should be used by calling
%    the command |\driver{|\meta{drivername}|}|.
% \changes{v3.5a}{2005/05/23}{Added 'PDFtex' option}
%    Possible choices are:
%    \begin{itemize}
%    \item DVItoLN03
%    \item DVItoPS
%    \item DVIps
%    \item em\TeX
%    \item \TeX tures
%    \item V\TeX
%    \item PDF\TeX
% \begin{changebar}
%    \item Xe\TeX
% \end{changebar}
%    \end{itemize}
%    This command can only be used in the preamble of the document.
%
%    The argument should be case-insensitive, so it is turned into
%    a string containing all uppercase characters. To keep some definitions
%    local, everything is done within a group.
% \changes{v3.1}{1993/07/02}{Removed some spurious spaces}
% \changes{v3.2c}{1996/03/26}{Reintroduced \cs{driver} in
%    compatibility mode} 
% \changes{v3.3e}{1998/02/24}{Added \cs{Textures}}
% \changes{v3.5a}{2005/05/23}{Added 'PDFtex' option}
%    \begin{macrocode}
\if@compatibility
  \def\driver#1{%
    \bgroup\edef\next{\def\noexpand\tempa{#1}}%
      \uppercase\expandafter{\next}%
      \def\LN{DVITOLN03}%
      \def\DVItoPS{DVITOPS}%
      \def\DVIPS{DVIPS}%
      \def\emTeX{EMTEX}%
      \def\Textures{TEXTURES}%
      \def\VTeX{VTEX}%
      \def\pdfTeX{PDFTEX}%
%    \end{macrocode}
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{Added 'XeTeX' option}
%    \begin{macrocode}
      \def\xeTeX{XETEX}
%    \end{macrocode}
% \end{changebar}
%    The choice has to be communicated to the macro
%    \verb=\cb@setup@specials= that will be called from within
%    \verb=\document=. For this purpose the control sequence
%    \verb=\cb@driver@setup= is used. It receives a numeric value
%    using \verb=\chardef=. 
%    \begin{macrocode}
      \global\chardef\cb@driver@setup=0\relax
      \ifx\tempa\LN       \global\chardef\cb@driver@setup=0\fi
      \ifx\tempa\DVItoPS  \global\chardef\cb@driver@setup=1\fi
      \ifx\tempa\DVIPS    \global\chardef\cb@driver@setup=2\fi
      \ifx\tempa\emTeX    \global\chardef\cb@driver@setup=3\fi
      \ifx\tempa\Textures \global\chardef\cb@driver@setup=4\fi
      \ifx\tempa\VTeX     \global\chardef\cb@driver@setup=5\fi
      \ifx\tempa\pdfTeX   \cb@pdftexcheck\fi
%    \end{macrocode}
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{Added 'XeTeX' option}
%    \begin{macrocode}
      \ifx\tempa\xeTeX    \cb@xetexcheck\fi
%    \end{macrocode}
% \end{changebar}
%    \begin{macrocode}
    \egroup}
%    \end{macrocode}
%    We add \verb+\driver+ to \verb+\@preamblecmds+, which is a
%    list of commands to be used only in the preamble of a document.
%    \begin{macrocode}
  {\def\do{\noexpand\do\noexpand}
    \xdef\@preamblecmds{\@preamblecmds \do\driver}
    }
\fi
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@setup@specials}
%    The macro |\cb@setup@specials| defines macros containing the
%    driver specific |\special| macros. It will be called from
%    within the |\begin{document}| command.
%
%  \begin{macro}{\cb@trace@defpoint}
%    When tracing is on, write information about the point being defined
%    to the log file.
% \changes{v3.3a}{1997/09/26}{use \cs{cb@trace} instead of \cs{wlog}}
%    \begin{macrocode}
\def\cb@trace@defpoint#1#2{%
  \cb@trace{%
    defining point \the#1 at position \the#2
    \MessageBreak
    cb@pagecount: \the\cb@pagecount; page \thepage}}
%    \end{macrocode}
%  \end{macro}
%
%
%  \begin{macro}{\cb@trace@connect}
%    When tracing is on, write information about the points being
%    connected to the log file.
% \changes{v3.3a}{1997/09/26}{use \cs{cb@trace} instead of \cs{wlog}}
%    \begin{macrocode}
\def\cb@trace@connect#1#2#3{%
  \cb@trace{%
    connecting points \the#1 and \the#2; barwidth: \the#3
    \MessageBreak
    cb@pagecount: \the\cb@pagecount; page \thepage}}
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\cb@defpoint}
%    The macro |\cb@defpoint| is used to define one of the two
%    points of a bar. It has two arguments, the number of the point
%    and the distance from the left side of the paper. Its syntax
%    is:
%    |\cb@defpoint{|\meta{number}|}{|\meta{length}|}|.
% \begin{macro}{\cb@resetpoints}
%    The macro |\cb@resetpoints| can be used to instruct the printer
%    driver that it should send a corresponding instruction to the
%    printer. This is really only used for the \textsf{LN03} printer.
%
% \begin{macro}{\cb@connect}
%    The macro |\cb@connect| is used to instruct the printer driver
%    to connect two points with a bar. The syntax is
%    |\cb@connect{|\meta{number}|}{|\meta{number}|}{|\meta{length}|}|
%    The two \meta{number}s indicate the two points to be connected;
%    the \meta{length} is the width of the bar.
%
%    \begin{macrocode}
\def\cb@setup@specials{%
%    \end{macrocode}
%    The control sequence |\cb@driver@setup| expands to a number which
%    indicates the driver that will be used.  The original
%    \file{changebar.sty} was written with only the |\special|
%    syntax of the program \texttt{DVItoLN03} (actually one of its
%    predecessors, \texttt{ln03dvi}). Therefore this syntax is defined
%    first.
%    \begin{macrocode}
\ifcase\cb@driver@setup
  \def\cb@defpoint##1##2{%
    \special{ln03:defpoint \the##1(\the##2,)}%
    \cb@trace@defpoint##1##2}
  \def\cb@connect##1##2##3{%
    \special{ln03:connect \the##1\space\space \the##2\space \the##3}%
    \cb@trace@connect##1##2##3}
  \def\cb@resetpoints{%
    \special{ln03:resetpoints \cb@minpoint \space\cb@maxpoint}}
%    \end{macrocode}
%    The first extension to the {changebar} option was for the
%    |\special| syntax of the program \texttt{DVItoPS} by James Clark.
%    \begin{macrocode}
\or
  \def\cb@defpoint##1##2{%
    \special{dvitops: inline
                \expandafter\cb@removedim\the##2\space 6.5536 mul\space
                /CBarX\the##1\space exch def currentpoint exch pop
                /CBarY\the##1\space exch def}%
    \cb@trace@defpoint##1##2}
%    \end{macrocode}
% \changes{v3.4b}{2001/08/29}{now use \cs{cb@ps@color} instead of
%    setting the greyness directly}
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \special{dvitops: inline
                gsave \cb@ps@color\space
                \expandafter\cb@removedim\the##3\space 6.5536 mul\space
                CBarX\the##1\space\space CBarY\the##1\space\space moveto
                CBarX\the##2\space\space CBarY\the##2\space\space lineto
                stroke grestore}%
    \cb@trace@connect##1##2##3}
  \let\cb@resetpoints\relax
%    \end{macrocode}
%    The program \texttt{DVIps} by Thomas Rokicki is also
%    supported. The PostScript code is nearly the same as for
%    \texttt{DVItoPS}, but the coordinate space has a different
%    dimension. Also this code has been made resolution independent,
%    whereas the code for \texttt{DVItoPS} might still be resolution
%    dependent.
%
%    So far all the positions have been calculated in \texttt{pt}
%    units.  DVIps uses pixels internally, so we have to convert
%    \texttt{pt}s into pixels which of course is done by dividing by
%    72.27 (\texttt{pt}s per inch) and multiplying by
%    \texttt{Resolution} giving the resolution of the
%    \textsc{PostScript} device in use as a \textsc{PostScript}
%    variable.
%    \begin{macrocode}
\or
  \def\cb@defpoint##1##2{%
     \special{ps:
                \expandafter\cb@removedim\the##2\space
                Resolution\space mul\space 72.27\space div\space
                /CBarX\the##1\space exch def currentpoint exch pop
                /CBarY\the##1\space exch def}%
    \cb@trace@defpoint##1##2}
%    \end{macrocode}
% \changes{v3.4b}{2001/08/29}{now use \cs{cb@ps@color} instead of
%    setting the greyness directly}
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \special{ps:
                gsave \cb@ps@color\space
                \expandafter\cb@removedim\the##3\space
                Resolution\space mul\space 72.27\space div\space
                setlinewidth
                CBarX\the##1\space\space CBarY\the##1\space\space moveto
                CBarX\the##2\space\space CBarY\the##2\space\space lineto
                stroke grestore}%
    \cb@trace@connect##1##2##3}
  \let\cb@resetpoints\relax
%    \end{macrocode}
%    The following addition is for the drivers written by Eberhard
%    Mattes.  The |\special| syntax used here is supported since
%    version 1.5 of his driver programs.
% \changes{v3.3a}{1997/09/24}{Removed warning about emTeX support from
%    dvidrv 1.5 upwards}  
% \changes{v3.3b}{1997/10/01}{em\TeX{} drivers have their origin in a
%    different position then dvips} 
% \changes{v3.3d}{1997/10/28}{Removed bogus offset}
%    \begin{macrocode}
\or
  \def\cb@defpoint##1##2{%
    \special{em:point \the##1,\the##2}%
    \cb@trace@defpoint##1##2}
  \def\cb@connect##1##2##3{%
    \special{em:line \the##1,\the##2,\the##3}%
    \cb@trace@connect##1##2##3}
  \let\cb@resetpoints\relax
%    \end{macrocode}
%
%    The following definitions are validated with \TeX tures
%    version~1.7.7, but will very likely also work with later
%    releases of \TeX tures. 
%
%    The \cs{cbdelete} command seemed to create degenerate lines
%    (i.e., lines of 0 length). PostScript will not render such lines
%    unless the linecap is set to 1, (semicircular ends) in which case
%    a filled circle is shown for such lines.
% \changes{v3.3e}{1998/02/24}{Added the definitions for textures
%    support}
% \changes{v3.5c}{2005/09/18}{A small change was submitted by Gordon
%    Lee from Blue Sky Systems}
%    \begin{macrocode}
\or
  \def\cb@defpoint##1##2{%
    \special{postscript 0 0 transform}% leave [x,y] on the stack
    \special{rawpostscript
                \expandafter\cb@removedim\the##2\space
                /CBarX\the##1\space exch def
                itransform exch pop
                /CBarY\the##1\space exch def}%
    \if@cb@trace\cb@trace@defpoint##1##2\fi}
%    \end{macrocode}
% \changes{v3.4b}{2001/08/29}{now use \cs{cb@ps@color} instead of
%    setting the greyness directly}
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \special{rawpostscript
                gsave 1 setlinecap \cb@ps@color\space
                \expandafter\cb@removedim\the##3\space
                setlinewidth
                CBarX\the##1\space\space CBarY\the##1\space\space moveto
                CBarX\the##2\space\space CBarY\the##2\space\space lineto
                stroke grestore}%
    \if@cb@trace\cb@trace@connect##1##2##3\fi}
  \let\cb@resetpoints\relax
%    \end{macrocode}
%    The following definitions were kindly provided by Michael Vulis.
% \changes{v3.4a}{2001/04/18}{Added the definitions for V\TeX\
%    support}
%    \begin{macrocode}
\or
  \def\cb@defpoint##1##2{%
    \special{pS:
                \expandafter\cb@removedim\the##2\space
                Resolution\space mul\space 72.27\space div\space
                /CBarX\the##1\space exch def currentpoint exch pop
                /CBarY\the##1\space exch def}%
    \cb@trace@defpoint##1##2}
%    \end{macrocode}
% \changes{v3.4b}{2001/08/29}{now use \cs{cb@ps@color} instead of
%    setting the greyness directly}
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \special{pS:
                gsave \cb@ps@color\space
                \expandafter\cb@removedim\the##3\space
                Resolution\space mul\space 72.27\space div\space
                setlinewidth
                CBarX\the##1\space\space CBarY\the##1\space\space moveto
                CBarX\the##2\space\space CBarY\the##2\space\space lineto
                stroke grestore}%
    \cb@trace@connect##1##2##3}
  \let\cb@resetpoints\relax
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{PDF\TeX{} support added}
%    The code for PDF\TeX{} is more elaborate as the calculations have to
%    be done in \TeX. |\cb@defpoint| will write information about the
%    coordinates of the point to the \file{.aux} file, from where it will
%    be picked up in the next run. Then we will construct the PDF
%    code necessary to draw the changebars.
%    \begin{macrocode}
\or
  \immediate\closeout\cb@writexy
  \immediate\openin\cb@readxy=\jobname.cb2\relax
%    \end{macrocode}
%
% \begin{macro}{\cb@pdfpoints}
% \begin{macro}{\cb@pdfpagenr}
%   The |\cb@pdfpoints| macro contains the list of coordinates of points
%   that have been read in memory from the \file{.cb2} file. The
%   |\cb@pdfpagenr| macro contains the next pagecount to be read in.
%    \begin{macrocode}
  \def\cb@pdfpoints{}
  \def\cb@pdfpagenr{0}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \begin{macro}{\cb@findpdfpoint}
%    The |\cb@findpdfpoint| macro finds the coordinates of point \#1 on
%    pagecount \#2. First we expand the arguments to get the real values.
%    \begin{macrocode}
  \def\cb@findpdfpoint##1##2{%
      \edef\cb@temp
        {\noexpand\cb@@findpdfpoint{\the##1}{\the##2}}%
      \cb@temp
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@@findpdfpoint}
%   The |\cb@@findpdfpoint| macro finds the coordinates of point \#1 on
%   pagecount \#2. If the information is not yet in memory is it read from
%   the \file{.cb2} file. The coordinates of the current point in the text
%   will be delivered in |\cb@pdfx| and |\cb@pdfy|, and |\cb@pdfz| will get
%   the x coordinate of the changebar. If the point is unknown, |\cb@pdfx|
%   will be set to |\relax|.
%    \begin{macrocode}
  \def\cb@@findpdfpoint##1##2{%
    \ifnum##2<\cb@pdfpagenr\relax\else
      \cb@pdfreadxy{##2}%
    \fi
    \let\cb@pdfx\relax
    \ifx\cb@pdfpoints\@empty\else
      \ifnum##2<0\relax
      \else
        \edef\cb@temp{\noexpand\cb@pdffind{##1}{##2}\cb@pdfpoints\relax{}}%
        \cb@temp
      \fi
    \fi
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@pdffind}
%    The |\cb@pdffind| recursively searches through |\cb@pdfpoints| to find
%    point \#1 on pagecount \#2.  |\cb@pdfpoints| contains entries of the
%    form \meta{pointnr}.\meta{pagecount}p\meta{x},\meta{y},\meta{z}pt.
%    When the point is found it is removed from |\cb@pdfpoints|. \#9
%    contains the cumulative head of the list to construct the new list
%    with the entry removed. \#3--\#8 are for pattern matching.
%    \begin{macrocode}
  \def\cb@pdffind##1##2##3.##4p##5,##6,##7pt##8\relax##9{%
    \def\cb@next{\cb@pdffind{##1}{##2}##8\relax{##9##3.##4p##5,##6,##7pt}}%
    \ifnum ##1=##3
      \ifnum ##2=##4
        \def\cb@pdfx{##5sp}%
        \def\cb@pdfy{##6sp}%
        \def\cb@pdfz{##7pt}%
        \let\cb@next\relax
        \gdef\cb@pdfpoints{##9##8}%
      \fi
    \fi
    \ifx\relax##8\relax
      \let\cb@next\relax
    \fi
    \cb@next
  }%
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@pdfreadxy}
%    The |\cb@pdfreadxy| macro reads lines from the \file{.cb2} file in
%    |\cb@pdfpoints| until the pagecount is greater than \#1 or the end of
%    the file is reached. This ensures that all entries belonging to the
%    current column are in memory.
%    \begin{macrocode}
  \def\cb@pdfreadxy##1{%
    \let\cb@next\relax
    \ifeof\cb@readxy
      \global\let\cb@pdfpagenr\cb@maxpoint
    \else
      {\endlinechar=-1\read\cb@readxy to\cb@temp
        \ifx\cb@temp\@empty\else
          \expandafter\cb@pdfparsexy\cb@temp
          \ifnum\cb@pdfpg<0\else
            \xdef\cb@pdfpoints{\cb@pdfpoints\cb@temp}%
            \cb@trace{PDFpoints=\cb@pdfpoints}%
            \global\let\cb@pdfpagenr\cb@pdfpg
          \fi
          \ifnum\cb@pdfpg>##1\else
            \global\def\cb@next{\cb@pdfreadxy{##1}}%
          \fi
        \fi
      }%
    \fi
    \cb@next
  }%
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@pdfparsexy}
%    The |\cb@pdfparsexy| macro extracts the pagecount from an entry read in
%    from the \file{.cb2} file.
%    \begin{macrocode}
  \def\cb@pdfparsexy##1.##2p##3,##4,##5pt{%
    \def\cb@pdfpg{##2}}%
%    \end{macrocode}
% \end{macro}
%
%    As PDF is not a programming language it does not have any variables to
%    remember the coordinates of the current point. Therefore we write the
%    information to the \file{.aux} file and read it in in the next run. We
%    write the x,y coordinates of the current point in the text and the x
%    coordinate of the change bar. 
%    We also need the value of |\cb@pagecount| here, not during the write.
%    \begin{macrocode}
  \def\cb@defpoint##1##2{%
    \if@filesw
      \begingroup
        \edef\point{{\the##1}{\the\cb@pagecount}}%
        \let\the=\z@
        \pdfsavepos
        \edef\cb@temp{\write\@auxout
          {\string\cb@pdfxy\point
            {\the\pdflastxpos}{\the\pdflastypos}{\the##2}}}%
        \cb@temp
      \endgroup
    \fi
    \cb@trace@defpoint##1##2%
  }%
%    \end{macrocode}
%
% \begin{macro}{\cb@cvtpct}
%    The macro |\cb@cvtpct| converts a percentage between 0 and 100 to a
%    decimal fraction.
%    \begin{macrocode}
  \def\cb@cvtpct##1{%
    \ifnum##1<0 0\else
    \ifnum##1>99 1\else
    \ifnum##1<10 0.0\the##1\else
    0.\the##1\fi\fi\fi}
%    \end{macrocode}
% \end{macro}
%
%    The |\cb@connect| finds the coordinates of the begin and end points,
%    converts them to PDF units and draws the bar with |\pdfliteral|. It
%    also sets the color or gray level, if necessary. When any of the
%    points is unknown the bar is skipped and a rerun is signalled.
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \cb@findpdfpoint{##1}\cb@pagecount
    \ifx\cb@pdfx\relax\cb@rerun
    \else
      \let\cb@pdftopy\cb@pdfy
      \cb@findpdfpoint{##2}\cb@pagecount
      \ifx\cb@pdfx\relax\cb@rerun
      \else
%    \end{macrocode}
%    We do everything in a group, so that we can freely use all kinds of
%    registers.
%    \begin{macrocode}
         \begingroup
           \cb@dima=\cb@pdfz
           \advance\cb@dima by-\cb@pdfx
           \advance\cb@dima by1in
           \cb@dima=0.996264009963\cb@dima\relax
%    \end{macrocode}
%    First we let PDF save the graphics state. Then we generate the color
%    selection code followed by the code to draw the changebar. Finally the
%    graphics state is restored. We cannot use the color commands from the
%    color package here, as the generated PDF code may be moved to the next
%    line.
%    \begin{macrocode}
           \ifx\cb@current@color\@undefined
             \def\cb@temp{\cb@cvtpct\c@changebargrey}%
             \pdfliteral{q \cb@temp\space g \cb@temp\space G}%
           \else
             \pdfliteral{q \cb@current@color}%
           \fi
           \edef\cb@temp{\expandafter\cb@removedim\the\cb@dima\space}%
           \cb@dima=\cb@pdftopy
           \advance\cb@dima-\cb@pdfy\relax
           \cb@dima=0.996264009963\cb@dima\relax
           ##3=0.996264009963##3\relax
           \pdfliteral direct{\expandafter\cb@removedim\the##3 w
             \cb@temp 0 m
             \cb@temp \expandafter\cb@removedim\the\cb@dima\space l S Q}%
        \endgroup
%    \end{macrocode}
%    We look up the two unused points to get them removed from |\cb@pdfpoints|.
%    \begin{macrocode}
        \cb@cntb=##1\relax
        \ifodd\cb@cntb\advance\cb@cntb 1\else\advance\cb@cntb -1\fi
        \cb@findpdfpoint\cb@cntb\cb@pagecount
        \cb@cntb=##2\relax
        \ifodd\cb@cntb\advance\cb@cntb 1\else\advance\cb@cntb -1\fi
        \cb@findpdfpoint\cb@cntb\cb@pagecount
      \fi
    \fi
    \cb@trace@connect##1##2##3%
  }%
%    \end{macrocode}
%
% \begin{macro}{\cb@checkPdfxy}
%    The macro |\cb@checkPdfxy| checks if the coordinates of a point have
%    changed during the current run. If so, we need to rerun \LaTeX.
%    \begin{macrocode}
  \gdef\cb@checkPdfxy##1##2##3##4##5{%
    \cb@@findpdfpoint{##1}{##2}%
    \ifnum##3=\cb@pdfx\relax
      \ifnum##4=\cb@pdfy\relax
        \ifdim##5=\cb@pdfz\relax
        \else
        \cb@error
        \fi
      \else
        \cb@error
      \fi
    \else
      \cb@error
    \fi
  }
%    \end{macrocode}
% \end{macro}
%
%    For PDF\TeX{} we don't need a limit on the number of bar points.
%    \begin{macrocode}
  \def\cb@maxpoint{9999999}
  \let\cb@resetpoints\relax
\or
%    \end{macrocode}
%
% \begin{changebar}
% \changes{v3.6a}{2011/04/30}{Xe\TeX{} support added}
%    The code for Xe\TeX{} is, like for PDF\TeX{}, more elaborate as
%    the calculations have to 
%    be done in \TeX. |\cb@defpoint| will write information about the
%    coordinates of the point to the \file{.aux} file, from where it will
%    be picked up in the next run. Then we will construct the PDF
%    code necessary to draw the changebars.
%    \begin{macrocode}
  \immediate\closeout\cb@writexy
  \immediate\openin\cb@readxy=\jobname.cb2\relax
%    \end{macrocode}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@pdfpoints}
% \begin{macro}{\cb@pdfpagenr}
%   The |\cb@pdfpoints| macro contains the list of coordinates of points
%   that have been read in memory from the \file{.cb2} file. The
%   |\cb@pdfpagenr| macro contains the next pagecount to be read in.
%    \begin{macrocode}
  \def\cb@pdfpoints{}
  \def\cb@pdfpagenr{0}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
%  \begin{macro}{\cb@findpdfpoint}
%    The |\cb@findpdfpoint| macro finds the coordinates of point \#1 on
%    pagecount \#2. First we expand the arguments to get the real values.
%    \begin{macrocode}
  \def\cb@findpdfpoint##1##2{%
      \edef\cb@temp
        {\noexpand\cb@@findpdfpoint{\the##1}{\the##2}}%
      \cb@temp
  }
%    \end{macrocode}
%  \end{macro}
% \end{changebar}
%
% \begin{changebar}
%  \begin{macro}{\pdfliteral}
%    For Xe\TeX{} we mimick PDF\TeX's command |\pdfliteral|.
%    \begin{macrocode}
  \def\pdfliteral##1{\special{pdf:literal ##1}}
%    \end{macrocode}
%  \end{macro}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@@findpdfpoint}
%   The |\cb@@findpdfpoint| macro finds the coordinates of point \#1 on
%   pagecount \#2. If the information is not yet in memory is it read from
%   the \file{.cb2} file. The coordinates of the current point in the text
%   will be delivered in |\cb@pdfx| and |\cb@pdfy|, and |\cb@pdfz| will get
%   the x coordinate of the changebar. If the point is unknown, |\cb@pdfx|
%   will be set to |\relax|.
%    \begin{macrocode}
  \def\cb@@findpdfpoint##1##2{%
    \ifnum##2<\cb@pdfpagenr\relax\else
      \cb@pdfreadxy{##2}%
    \fi
    \let\cb@pdfx\relax
    \ifx\cb@pdfpoints\@empty\else
      \ifnum##2<0\relax
      \else
        \edef\cb@temp{\noexpand\cb@pdffind{##1}{##2}\cb@pdfpoints\relax{}}%
        \cb@temp
      \fi
    \fi
  }
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@pdffind}
%    The |\cb@pdffind| recursively searches through |\cb@pdfpoints| to find
%    point \#1 on pagecount \#2.  |\cb@pdfpoints| contains entries of the
%    form \meta{pointnr}.\meta{pagecount}p\meta{x},\meta{y},\meta{z}pt.
%    When the point is found it is removed from |\cb@pdfpoints|. \#9
%    contains the cumulative head of the list to construct the new list
%    with the entry removed. \#3--\#8 are for pattern matching.
%    \begin{macrocode}
  \def\cb@pdffind##1##2##3.##4p##5,##6,##7pt##8\relax##9{%
    \def\cb@next{\cb@pdffind{##1}{##2}##8\relax{##9##3.##4p##5,##6,##7pt}}%
    \ifnum ##1=##3
      \ifnum ##2=##4
        \def\cb@pdfx{##5sp}%
        \def\cb@pdfy{##6sp}%
        \def\cb@pdfz{##7pt}%
        \let\cb@next\relax
        \gdef\cb@pdfpoints{##9##8}%
      \fi
    \fi
    \ifx\relax##8\relax
      \let\cb@next\relax
    \fi
    \cb@next
  }%
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@pdfreadxy}
%    The |\cb@pdfreadxy| macro reads lines from the \file{.cb2} file in
%    |\cb@pdfpoints| until the pagecount is greater than \#1 or the end of
%    the file is reached. This ensures that all entries belonging to the
%    current column are in memory.
%    \begin{macrocode}
  \def\cb@pdfreadxy##1{%
    \let\cb@next\relax
    \ifeof\cb@readxy
      \global\let\cb@pdfpagenr\cb@maxpoint
    \else
      {\endlinechar=-1\read\cb@readxy to\cb@temp
        \ifx\cb@temp\@empty\else
          \expandafter\cb@pdfparsexy\cb@temp
          \ifnum\cb@pdfpg<0\else
            \xdef\cb@pdfpoints{\cb@pdfpoints\cb@temp}%
            \cb@trace{PDFpoints=\cb@pdfpoints}%
            \global\let\cb@pdfpagenr\cb@pdfpg
          \fi
          \ifnum\cb@pdfpg>##1\else
            \global\def\cb@next{\cb@pdfreadxy{##1}}%
          \fi
        \fi
      }%
    \fi
    \cb@next
  }%
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@pdfparsexy}
%    The |\cb@pdfparsexy| macro extracts the pagecount from an entry read in
%    from the \file{.cb2} file.
%    \begin{macrocode}
  \def\cb@pdfparsexy##1.##2p##3,##4,##5pt{%
    \def\cb@pdfpg{##2}}%
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
%    As PDF is not a programming language it does not have any variables to
%    remember the coordinates of the current point. Therefore we write the
%    information to the \file{.aux} file and read it in in the next run. We
%    write the x,y coordinates of the current point in the text and the x
%    coordinate of the change bar. 
%    We also need the value of |\cb@pagecount| here, not during the write.
%    \begin{macrocode}
  \def\cb@defpoint##1##2{%
    \if@filesw
      \begingroup
        \edef\point{{\the##1}{\the\cb@pagecount}}%
        \let\the=\z@
        \pdfsavepos
        \edef\cb@temp{\write\@auxout
          {\string\cb@pdfxy\point
            {\the\pdflastxpos}{\the\pdflastypos}{\the##2}}}%
        \cb@temp
      \endgroup
    \fi
    \cb@trace@defpoint##1##2%
  }%
%    \end{macrocode}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@cvtpct}
%    The macro |\cb@cvtpct| converts a percentage between 0 and 100 to a
%    decimal fraction.
%    \begin{macrocode}
  \def\cb@cvtpct##1{%
    \ifnum##1<0 0\else
    \ifnum##1>99 1\else
    \ifnum##1<10 0.0\the##1\else
    0.\the##1\fi\fi\fi}
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@pdf@scale}
% \changes{v3.6a}{2018/02/03}{Added macro for scale factor}
%    In order to get things in the rightspot we need a little scaling
%    factor. We define it here.
%    \begin{macrocode}
\def\cb@pdf@scale{0.996264009963}
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
%    The |\cb@connect| finds the coordinates of the begin and end points,
%    converts them to PDF units and draws the bar with |\pdfliteral|. It
%    also sets the color or gray level, if necessary. When any of the
%    points is unknown the bar is skipped and a rerun is signalled.
%    \begin{macrocode}
  \def\cb@connect##1##2##3{%
    \cb@findpdfpoint{##1}\cb@pagecount
    \ifx\cb@pdfx\relax\cb@rerun
    \else
      \let\cb@pdftopy\cb@pdfy
      \cb@findpdfpoint{##2}\cb@pagecount
      \ifx\cb@pdfx\relax\cb@rerun
      \else
%    \end{macrocode}
%    We do everything in a group, so that we can freely use all kinds of
%    registers.
%    \begin{macrocode}
         \begingroup
           \cb@dima=\cb@pdfz
           \advance\cb@dima by-\cb@pdfx
           \advance\cb@dima by1in
           \cb@dima=\cb@pdf@scale\cb@dima\relax
%    \end{macrocode}
%    First we let PDF save the graphics state. Then we generate the color
%    selection code followed by the code to draw the changebar. Finally the
%    graphics state is restored. We cannot use the color commands from the
%    color package here, as the generated PDF code may be moved to the next
%    line.
%    \begin{macrocode}
           \ifx\cb@current@color\@undefined
             \def\cb@temp{\cb@cvtpct\c@changebargrey}%
             \pdfliteral{q \cb@temp\space g \cb@temp\space G}%
           \else
             \pdfliteral{q \expandafter\sec@nd@ftw@\cb@current@color\space RG 
                           \expandafter\sec@nd@ftw@\cb@current@color\space rg}%
           \fi
           \edef\cb@temp{\expandafter\cb@removedim\the\cb@dima\space}%
           \cb@dima=\cb@pdftopy
           \advance\cb@dima-\cb@pdfy\relax
           \cb@dima=\cb@pdf@scale\cb@dima\relax
           ##3=\cb@pdf@scale##3\relax
           \pdfliteral{\expandafter\cb@removedim\the##3 w
             \cb@temp 0 m
             \cb@temp \expandafter\cb@removedim\the\cb@dima\space l S Q}%
        \endgroup
%    \end{macrocode}
%    We look up the two unused points to get them removed from |\cb@pdfpoints|.
%    \begin{macrocode}
        \cb@cntb=##1\relax
        \ifodd\cb@cntb\advance\cb@cntb 1\else\advance\cb@cntb -1\fi
        \cb@findpdfpoint\cb@cntb\cb@pagecount
        \cb@cntb=##2\relax
        \ifodd\cb@cntb\advance\cb@cntb 1\else\advance\cb@cntb -1\fi
        \cb@findpdfpoint\cb@cntb\cb@pagecount
      \fi
    \fi
    \cb@trace@connect##1##2##3%
  }%
%    \end{macrocode}
% \end{changebar}
%
% \begin{changebar}
% \begin{macro}{\cb@checkPdfxy}
%    The macro |\cb@checkPdfxy| checks if the coordinates of a point have
%    changed during the current run. If so, we need to rerun \LaTeX.
%    \begin{macrocode}
  \gdef\cb@checkPdfxy##1##2##3##4##5{%
    \cb@@findpdfpoint{##1}{##2}%
    \ifnum##3=\cb@pdfx\relax
      \ifnum##4=\cb@pdfy\relax
        \ifdim##5=\cb@pdfz\relax
        \else
        \cb@error
        \fi
      \else
        \cb@error
      \fi
    \else
      \cb@error
    \fi
  }
%    \end{macrocode}
% \end{macro}
% \end{changebar}
%
% \begin{changebar}
%    For Xe\TeX{} we don't need a limit on the number of bar points.
%    \begin{macrocode}
  \def\cb@maxpoint{9999999}
  \let\cb@resetpoints\relax
%    \end{macrocode}
% \end{changebar}
%
%    When code for other drivers should be added it can be inserted
%    here.  When someone makes a mistake and somehow selects an
%    unknown driver a warning is issued and the macros are defined to
%    be no-ops.
%    \begin{macrocode}
\else
  \PackageWarning{Changebar}{changebars not supported in unknown setup}
  \def\cb@defpoint##1##2{\cb@trace@defpoint##1##2}
  \def\cb@connect##1##2##3{\cb@trace@connect##1##2##3}
  \let\cb@resetpoints\relax
\fi
%    \end{macrocode}
%    The last thing to do is to forget about |\cb@setup@specials|.
%    \begin{macrocode}
\global\let\cb@setup@specials\relax}
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\cbstart}
%    The macro |\cbstart| starts a new changebar. It has an (optional)
%    argument that will be used to determine the width of the bar.
%    The default width is |\changebarwidth|.
% \changes{v3.3i}{1999/06/19}{Use \LaTeX's own mechanism to detect
%    grouping errors.}
% \changes{v3.4e}{2002/10/28}{Reverted the change from version 3.3i} 
%    \begin{macrocode}
\newcommand*{\cbstart}{\@ifnextchar [%]
                        {\cb@start}%
                        {\cb@start[\changebarwidth]}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cbend}
%    The macro |\cbend| (surprisingly) ends a changebar. The macros
%    |\cbstart| and |\cbend| can be used when the use of a
%    proper \LaTeX\ environment is not possible.
%    \begin{macrocode}
\newcommand*{\cbend}{\cb@end}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cbdelete}
%    The macro |\cbdelete| inserts a `deletebar' in the margin.
%    It too has an optional argument to determine the width of the bar.
%    The default width (and length) of it are stored in
%    |\deletebarwidth|.
%    \begin{macrocode}
\newcommand*{\cbdelete}{\@ifnextchar [%]
  {\cb@delete}%
  {\cb@delete[\deletebarwidth]}}
%    \end{macrocode}
%
% \begin{macro}{\cb@delete}
%    Deletebars are implemented as a special `change bar'. The bar
%    is started and immediately ended. It is as long as it is wide.
%    \begin{macrocode}
\def\cb@delete[#1]{\vbox to \z@{\vss\cb@start[#1]\vskip #1\cb@end}}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\changebar}
% \begin{macro}{\endchangebar}
%    The macros |\changebar| and |\endchangebar| have the same
%    function as |\cbstart| and |\cbend| but they can be used as a
%    \LaTeX\ environment to enforce correct nesting.  They can
%    \emph{not} be used in the \textsf{tabular} and \textsf{tabbing}
%    environments.
%    \begin{macrocode}
\newenvironment{changebar}%
               {\@ifnextchar [{\cb@start}%
                              {\cb@start[\changebarwidth]}}%
               {\cb@end}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\nochangebars}
%    To disable changebars altogether without having to remove them
%    from the document the macro |\nochangebars| is provided. It makes
%    no-ops of three internal macros.
%    \begin{macrocode}
\newcommand*{\nochangebars}{%
  \def\cb@start[##1]{}%
  \def\cb@delete[##1]{}%
  \let\cb@end\relax}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\changebarwidth}
%    The default width of the changebars is stored in the dimension
%    register |\changebarwidth|.
%    \begin{macrocode}
\newlength{\changebarwidth}
\setlength{\changebarwidth}{2pt}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\deletebarwidth}
%    The default width of the deletebars is stored in the dimension
%    register |\deletebarwidth|.
%    \begin{macrocode}
\newlength{\deletebarwidth}
\setlength{\deletebarwidth}{4pt}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\changebarsep}
%    The default separation between all bars and the text is stored in
%    the dimen register |\changebarsep|.
% \changes{v3.6b}{2018/02/04}{set the default separtion between text
%    and changebars to half the separation between text and marginal
%    paragraphs} 
%    \begin{macrocode}
\newlength{\changebarsep}
\setlength{\changebarsep}{0.5\marginparsep}
%    \end{macrocode}
% \end{macro}
%
% \begin{Var}{changebargrey}
%    When the document is printed using one of the PostScript drivers
%    the bars do not need to be black; with PostScript it is possible
%    to have grey, and colored, bars. The percentage of greyness of the
%    bar is stored in the count register |\changebargrey|. It can
%    have values between $0$ (meaning white) and $100$ (meaning
%    black).
%
%    \begin{macrocode}
\newcounter{changebargrey}
\setcounter{changebargrey}{65}
%    \end{macrocode}
% \end{Var}
%
%    When one of the options \Lopt{color} or \Lopt{xcolor} was
%    selected we need to load the appropriate package. When we're run
%    by pdf\LaTeX\ we need to pass that information on to that package.
% \changes{v3.4e}{2001/09/14}{Detect pdf mode}
% \changes{v3.5a}{2005/05/23}{The option \Lopt{pdftex} will be supplied
%    automatically with the current color packages. Leave out
%    \Lopt{dvipsnames} as it is usually automatically loaded and may clash
%    if the color or xcolor package has already been loaded. Also
%    \cs{cb@color@pkg} is undefined when no color option has been given.}
%    \begin{macrocode}
\@ifpackagewith{changebar}{\csname cb@color@pkg\endcsname}{%
    \RequirePackage{\cb@color@pkg}%
%    \end{macrocode}
%    Then we need to define the command |\cbcolor| which is a slightly
%    modified copy of the command |\color| from the \pkg{color}
%    package.
%
% \begin{macro}{\cbcolor}
%    |\cbcolor{|\emph{declared-colour}|}| switches the colour of the
%    changebars to \emph{declared-colour}, which must previously have
%    been defined using |\definecolor|. This colour will stay in
%    effect until the end of the current \TeX\ group.
%
%    |\cbcolor[|\emph{model}|]{|\emph{colour-specification}|}| is
%    similar to the above, but uses a colour not declared by
%    |\definecolor|. The allowed \emph{model}'s vary depending on the
%    driver. The syntax of the \emph{colour-specification} argument
%    depends on the model.
%    \begin{macrocode}
  \DeclareRobustCommand\cbcolor{%
    \@ifnextchar[\@undeclaredcbcolor\@declaredcbcolor}
%    \end{macrocode}
%  \end{macro}
%
%  \begin{macro}{\@undeclaredcbcolor}
%    Call the driver-dependent command |\color@|\meta{model} to define
%    |\cb@current@color|.
% \changes{v3.5c}{2005/09/18}{Use the higher level interface throug
%    \cs{color} to prevent problemns with \texttt{color.sty} or
%    \texttt{xcolor.sty}}
%    \begin{macrocode}
  \def\@undeclaredcbcolor[#1]#2{%
    \begingroup
      \color[#1]{#2}%
      \global\let\cb@current@color\current@color
    \endgroup
    \ignorespaces
    }
%    \end{macrocode}
%  \end{macro}
%
%  \begin{macro}{\@declaredcbcolor}
% \changes{v3.5c}{2005/09/18}{Use the higher level interface throug
%    \cs{color} to prevent problemns with \texttt{color.sty} or
%    \texttt{xcolor.sty}}
%    \begin{macrocode}
  \def\@declaredcbcolor#1{%
    \begingroup
      \color{#1}%
      \global\let\cb@current@color\current@color
    \endgroup
    \ignorespaces}%
  }{%
%    \end{macrocode}
%    When the \Lopt{color} option wasn't specified the usage of the
%    |\cbcolor| command results in a warning message.
% \changes{v3.4d}{2001/09/04}{Isue an error when \cmd{cbcolor} is
%    used without specifying the \Lopt{color} option}
% \changes{v3.4e}{2001/09/07}{Made the error message a warning message}
%    \begin{macrocode}
  \def\cbcolor{\@ifnextchar[%]
    \@@cbcolor\@cbcolor}%
  \def\@@cbcolor[#1]#2{\cb@colwarn\def\@@cbcolor[##1]##2{}}%
  \def\@cbcolor#1{\cb@colwarn\def\@cbcolor##1{}}%
  \def\cb@colwarn{\PackageWarning{Changebar}%
    {You didn't specify the option `color';\MessageBreak
      your command \string\cbcolor\space will be ignored}}%
  }
%    \end{macrocode}
%  \end{macro}
%
% \subsection{Macros for beginning and ending bars}
%
% \begin{macro}{\cb@start}
%    This macro starts a change bar.  It assigns a new value to the
%    current point and advances the counter for the next point to be
%    assigned.  It pushes this info onto |\cb@currentstack| and then
%    sets the point by calling |\cb@setBeginPoints| with the point
%    number.  Finally, it writes the \file{.aux} file.
% \changes{v3.3h}{1999/06/15}{Added \cs{cb@checkpage} to find final
%    page from history}
%    \begin{macrocode}
\def\cb@start[#1]{%
  \cb@topleft=\cb@nextpoint
%    \end{macrocode}
%    Store the width of the< current bar in |\cb@curbarwd|.
%    \begin{macrocode}
  \cb@curbarwd#1\relax
  \cb@push\cb@currentstack
%    \end{macrocode}
%    Now find out on which page the start of this bar finaly ends up;
%    due to the asynchronous nature of the output routine it might be
%    a different page. The macro |\cb@checkpage| finds the page number
%    on the history stack.
% \changes{v3.5a}{2005/05/23}{Correction for nested changebars}
%    \begin{macrocode}
  \cb@checkpage\z@
%    \end{macrocode}
%    Temporarily assign the page number to |\cb@pagecount| as that
%    register is used by |\cb@setBeginPoints|. Note that it's value is
%    offset by one from the page counter.
%    \begin{macrocode}
  \cb@cnta\cb@pagecount
  \cb@pagecount\cb@page\advance\cb@pagecount\m@ne
  \ifvmode 
    \cb@setBeginPoints
  \else
    \vbox to \z@{%
%    \end{macrocode}
%    When we are in horizontal mode we jump up a line to set the
%    starting point of the changebar.
%    \begin{macrocode}
      \vskip -\ht\strutbox
      \cb@setBeginPoints
      \vskip \ht\strutbox}%
  \fi
%    \end{macrocode}
%    Restore |\cb@pagecount|.
%    \begin{macrocode}
  \cb@pagecount\cb@cnta
  \cb@advancePoint}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@advancePoint}
%    The macro |\cb@advancePoint| advances the count register
%    |\cb@nextpoint|. When the maximum number is reached, the
%    numbering is reset.
%    \begin{macrocode}
\def\cb@advancePoint{%
  \global\advance\cb@nextpoint by 4\relax
  \ifnum\cb@nextpoint>\cb@maxpoint
    \global\cb@nextpoint=\cb@minpoint\relax
  \fi}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@end}
%    This macro ends a changebar. It pops the current point and
%    nesting level off |\cb@currentstack| and sets the end point by
%    calling |\cb@setEndPoints| with the parameter corresponding to
%    the \emph{beginning} point number. It writes the \file{.aux} file
%    and joins the points.
%    When in horizontal mode we put the call to |\cb@setEndPoints|
%    inside a |\vadjust|. This ensures that things with a large depth,
%    e.g. a parbox or formula will be completely covered. By default
%    these have their baseline centered, and thus otherwise the
%    changebar would stop there.
%
% \changes{v3.3a}{1997/09/26}{Added \cs{ignorespaces}}
% \changes{v3.3g}{1999/06/11}{Added stack tracing}
% \changes{v3.3h}{1999/06/15}{Now check the history stack to find the
%    page on which this point ends up}
% \changes{v3.5a}{2005/05/23}{Added \cs{vadjust} in horizontal mode.}
%    \begin{macrocode}
\def\cb@end{%
  \cb@trace@stack{end of bar on page \the\c@page}%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
    \PackageWarning{Changebar}%
      {Badly nested changebars; Expect erroneous results}%
  \else
%    \end{macrocode}
%    Call |\cb@checkpage| to find the page this point finally ends up
%    on.
% \changes{v3.5a}{2005/05/23}{Correction for nested changebars}
%    \begin{macrocode}
    \cb@checkpage\thr@@
%    \end{macrocode}
%    Again, we need to temporarily overwrite |\cb@pagecount|.
%    \begin{macrocode}
    \cb@cnta\cb@pagecount
    \cb@pagecount\cb@page\advance\cb@pagecount\m@ne
    \ifvmode
      \cb@setEndPoints
    \else
      \vadjust{\cb@setEndPoints}%
    \fi
    \cb@pagecount\cb@cnta
  \fi
  \ignorespaces}
%    \end{macrocode}
%\end{macro}
%
%  \begin{macro}{\cb@checkpage}
% \changes{v3.3h}{1999/06/15}{Macro added}
%    The macro |\cb@checkpage| checks the history stack in order to
%    find out on which page a set of points finaly ends up.
%
%    We expect the identification of the points in |\cb@topleft| and
%    |\cb@page|. The resulting page will be stored in |\cb@page|.
%    The parameter indicates whether we are searching for a begin
%    point (0) or end point (3).
% \changes{v3.3i}{1999/06/18}{Check for and handle the situation that
%    the history stack is too short due to new bars added to a
%    document}
% \changes{v3.5a}{2005/05/23}{Correction for nested changebars}
%    \begin{macrocode}
\def\cb@checkpage#1{%
%    \end{macrocode}
%    First store the identifiers in temporary registers.
%    \begin{macrocode}
  \cb@cnta\cb@topleft\relax
  \advance\cb@cnta by #1\relax
  \cb@cntb\cb@page\relax
  \cb@dima\cb@curbarwd\relax
%    \end{macrocode}
%    Then pop the history stack.
%    \begin{macrocode}
  \cb@pop\cb@historystack
%    \end{macrocode}
%    If it was empty there is nothing to check and we're done.
%    \begin{macrocode}
  \ifnum\cb@topleft=\cb@nil
  \else
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Correction for moving floats}
%    Now keep popping the stack until |\cb@topleft| is found. The values
%    popped from the stack are pushed on a temporary stack to be pushed
%    back later. This could perhaps be implemented more efficiently if
%    the stacks had a different design.
%    \begin{macrocode}
    \cb@FindPageNum
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Correction for nested changebars}
%    \begin{macrocode}
    \ifnum\cb@topleft>\cb@maxpoint\else
%    \end{macrocode}
%    Now that we've found it overwrite |\cb@cntb| with the
%    |\cb@page| from the stack.
%    \begin{macrocode}
      \cb@cntb\cb@page
    \fi
%    \end{macrocode}
%    Now we restore the history stack to it's original state.
%    \begin{macrocode}
    \@whilenum\cb@topleft>\cb@nil\do{%
      \cb@push\cb@historystack
      \cb@pop\cb@tempstack}%
  \fi
%    \end{macrocode}
%    Finally return the correct values
% \changes{v3.5a}{2005/05/23}{Correction for nested changebars}
%    \begin{macrocode}
  \advance\cb@cnta by -#1\relax
  \cb@topleft\cb@cnta\relax
  \cb@page\cb@cntb\relax
  \cb@curbarwd\cb@dima\relax
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@FindPageNum}
%    |\cb@FindPageNum| recursively searches through the history stack until
%    an entry is found that is equal to |\cb@cnta|.
%    \begin{macrocode}
\def\cb@FindPageNum{%
  \ifnum\cb@topleft=\cb@cnta
%    \end{macrocode}
%    We have found it, exit the macro, otherwise push the current entry on
%    the temporary stack and pop a new one from the history stack.
%    \begin{macrocode}
  \else
    \cb@push\cb@tempstack
    \cb@pop\cb@historystack
%    \end{macrocode}
%    When the user adds changebars to his document we might run out of
%    the history stack before we find a match. This would send \TeX\
%    into an endless loop if it wasn't detected and handled.
%    \begin{macrocode}
    \ifnum\cb@topleft=\cb@nil
      \cb@trace{Ran out of history stack, new changebar?}%
%    \end{macrocode}
%    In this case we give |\cb@topleft| an `impossible value' to
%    remember this special situation.
%    \begin{macrocode}
      \cb@topleft\cb@maxpoint\advance\cb@topleft\@ne
    \else
%    \end{macrocode}
%    Recursively call ourselves.
%    \begin{macrocode}
      \expandafter\expandafter\expandafter\cb@FindPageNum
    \fi
  \fi
  }%
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@setBeginPoints}
% \changes{v3.3a}{1997/09/26}{Renamed from \cs{cb@setBeginPoint} and
%    removed parameter; use new dimension register for positioning} 
%    The macro |\cb@setBeginPoints| assigns a position to the top left
%    and top right points. It determines wether the point is on an even
%    or an odd page and uses the right dimension to position the
%    point. Keep in mind that the value of |\cb@pagecount| is one
%    less than the value of |\c@page| unless the latter has been reset
%    by the user. 
%
%    The top left point is used to write an entry on the \file{.aux}
%    file to create the history stack on the next run.
% \changes{v3.5a}{2005/05/23}{Correction for mixed onecolumn and twocolumn
%                documents and page number changes}
%    \begin{macrocode}
\def\cb@setBeginPoints{%
  \cb@topright=\cb@topleft\advance\cb@topright by\@ne
  \cb@cntb=\cb@pagecount
  \divide\cb@cntb by\tw@
  \ifodd\cb@cntb
    \cb@defpoint\cb@topleft\cb@even@left
    \cb@defpoint\cb@topright\cb@even@right
  \else
    \cb@defpoint\cb@topleft\cb@odd@left
    \cb@defpoint\cb@topright\cb@odd@right
  \fi
  \cb@writeAux\cb@topleft
  }
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@setEndPoints}
% \changes{v3.3a}{1997/09/26}{Renamed from \cs{cb@setEndPoint} and
%    removed parameter; use new dimension register for positioning} 
%    The macro |\cb@setEndPoints| assigns positions to the bottom
%    points for a change bar. It then instructs the driver to connect
%    two points with a bar. The macro assumes that the width of the
%    bar is stored in |\cb@curbarwd|. 
%
%    The bottom right point is used to write to the \file{.aux} file
%    to signal the end of the current bar on the history stack.
% \changes{v3.3g}{1999/06/12}{Take the setting of \Lopt{twoside} into
%    account}
% \changes{v3.5a}{2005/05/23}{The test for \Lopt{twoside} is really
%    unnecessary if the even side is always chosen for an even page}
% \changes{v3.5a}{2005/05/23}{Correction for mixed onecolumn and twocolumn
%    documents and page number changes}
%    \begin{macrocode}
\def\cb@setEndPoints{%
  \cb@topright=\cb@topleft\advance\cb@topright by\@ne
  \cb@botleft=\cb@topleft\advance\cb@botleft by\tw@
  \cb@botright=\cb@topleft\advance\cb@botright by\thr@@
   \cb@cntb=\cb@pagecount
  \divide\cb@cntb by\tw@
  \ifodd\cb@cntb
    \cb@defpoint\cb@botleft\cb@even@left
    \cb@defpoint\cb@botright\cb@even@right
  \else
    \cb@defpoint\cb@botleft\cb@odd@left
    \cb@defpoint\cb@botright\cb@odd@right
  \fi
  \cb@writeAux\cb@botright
  \edef\cb@leftbar{%
    \noexpand\cb@connect{\cb@topleft}{\cb@botleft}{\cb@curbarwd}}%
  \edef\cb@rightbar{%
    \noexpand\cb@connect{\cb@topright}{\cb@botright}{\cb@curbarwd}}%
%    \end{macrocode}
% \changes{v3.3a}{1997/09/26}{Added support for typesetting twocolumn
%    text with changebars} 
% \changes{v3.5a}{2005/05/23}{Checking |@firstcolumn| outside the output
%    routine is unreliable; check \cs{cb@pagecount} instead}
%    In twocolumn pages always use outerbars
%    \begin{macrocode}
  \if@twocolumn
     \ifodd\cb@pagecount\cb@rightbar\else\cb@leftbar\fi
%    \end{macrocode}
%    
% \changes{v3.4e}{2001/09/07}{The \cs{outerbars} conditional should be
%    inside an \cs{else} clause}
% \changes{v3.5a}{2005/05/23}{Series of \cs{if}s replaced by
%    \cs{ifcase} on \cs{cb@barsplace}}
%    \begin{macrocode}
  \else
    \ifcase\cb@barsplace
%    \end{macrocode}
%    0=innerbars
%    \begin{macrocode}
      \ifodd\cb@cntb
        \cb@rightbar
      \else
        \if@twoside\cb@leftbar\else\cb@rightbar\fi
      \fi
    \or
%    \end{macrocode}
%    1=outerbars
%    \begin{macrocode}
      \ifodd\cb@cntb
        \cb@leftbar
      \else
        \if@twoside\cb@rightbar\else\cb@leftbar\fi
      \fi
    \or
%    \end{macrocode}
%    2=leftbars
%    \begin{macrocode}
      \cb@leftbar
    \or
%    \end{macrocode}
%    3=rightbars
%    \begin{macrocode}
      \cb@rightbar
    \fi
  \fi
  }%
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@writeAux}
%    The macro |\cb@writeAux| writes information about a changebar
%    point to the auxiliary file. The number of the point, the
%    pagenumber and the width of the bar are written out as arguments
%    to |\cb@barpoint|. This latter macro will be expanded when the
%    auxiliary file is read in.  The macro assumes that the width of
%    bar is stored in |\cb@curbarwd|.
%
%    The code is only executed when auxiliary files are enabled, as
%    there's no sense in trying to write to an unopened file.
%    \begin{macrocode}
\def\cb@writeAux#1{%
  \if@filesw
    \begingroup
      \edef\point{\the#1}%
      \edef\level{\the\cb@curbarwd}%
      \let\the=\z@
      \edef\cb@temp{\write\@auxout
        {\string\cb@barpoint{\point}{\the\cb@pagecount}{\level}}}%
      \cb@temp
    \endgroup
  \fi}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Macros for Making It Work Across Page Breaks}
% \label{pagebreak}
%
% \changes{v3.5a}{2005/05/23}{Changes for twocolumn support: Detect page
%    number changes in righthand columns.}
% \begin{Var}{@cb@pagejump}
%    A switch to indicate that we have made a page correction.
%    \begin{macrocode}
\newif\if@cb@pagejump
%    \end{macrocode}
% \end{Var}
% \begin{macro}{\cb@pagejumplist}
%    The list of pagecounts to be corrected.
%    \begin{macrocode}
\def\cb@pagejumplst{-1}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\cb@nextpagejump}
%    The next pagecount from the list.
%    \begin{macrocode}
\def\cb@nextpagejump{-1}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\cb@pagejump}
%    This macro is written to the \file{.aux} file when a pagecount in a
%    lefthand column should be corrected. The argument is the incorrect
%    pagecount. 
%    \begin{macrocode}
\def\cb@pagejump#1{\xdef\cb@pagejumplst{\cb@pagejumplst,#1}}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\cb@writepagejump}
%    This macro writes a |\cb@pagejump| entry to the \file{.aux} file.
%    It does it by putting the |\write| command in the |\@leftcolumn| so
%    that it will be properly positioned relative to the bar points.
%    \begin{macrocode}
\def\cb@writepagejump#1{
  \cb@cntb=\cb@pagecount
  \advance\cb@cntb by#1\relax
  \global\setbox\@leftcolumn\vbox to\@colht{%
    \edef\cb@temp{\write\@auxout{\string\cb@pagejump{\the\cb@cntb}}}%
    \cb@temp
    \dimen@ \dp\@leftcolumn
    \unvbox \@leftcolumn
    \vskip -\dimen@
  }%
}
%    \end{macrocode}
% \end{macro}
% \begin{macro}{\cb@poppagejump}
%    Pop an entry from |pagejumplst|. The entry is put in |\cb@nextpagejump|.
%    \begin{macrocode}
\def\cb@poppagejump#1,#2\relax{%
  \gdef\cb@nextpagejump{#1}%
  \gdef\cb@pagejumplst{#2}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@checkpagecount}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    This macro checks that |\cb@pagecount| is correct at the beginning of
%    a column or page.
%    First we ensure that |\cb@pagecount| has the proper parity: odd in the
%    righthand column of a twocolumn page, even in the lefthand column of a
%    twocolumn page and in onecolumn pages.
%    \begin{macrocode}
\def\cb@checkpagecount{%
  \if@twocolumn
    \if@firstcolumn
      \ifodd\cb@pagecount\global\advance\cb@pagecount by\@ne\fi
    \fi
  \else
    \ifodd\cb@pagecount\global\advance\cb@pagecount by\@ne\fi
  \fi
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    Also, in twosided documents, |\cb@pagecount|/2 must be odd on even pages
%    and even on odd pages. If necessary, increase |\cb@pagecount| by 2. For
%    onesided documents, we don't do this as it doesn't matter (but it
%    would be harmless).
%    In the righthand column in twoside documents we must check if
%    |\cb@pagecount|/2 has the proper parity (see below).   
%    If it is incorrect, the page number has changed after the lefthand
%    column, so |\cb@pagecount| is incorrect there. Therefore we write a
%    command in the \file{.aux} file so that in the next run the lefthand
%    column will correct its |\cb@pagecount|. We also need to signal
%    a rerun. If the correction was
%    made in the lefthand column, the flag |@cb@pagejump| is set, and we have
%    to be careful in the righthand column. If in the righthand column the
%    flag is set and  |\cb@pagecount| is correct, the correction in the
%    lefthand column worked, but we still have to write into the
%    \file{.aux} file for the next run. If on the other hand
%    |\cb@pagecount| is incorrect while the flag is set, apparently the
%    correction in the lefthand column should not have been done (probably
%    because the document has changed), so we do nothing.
%    \begin{macrocode}
  \if@twoside
    \cb@cntb=\cb@pagecount
    \divide\cb@cntb by\tw@
    \advance\cb@cntb by-\c@page
    \ifodd\cb@cntb
%    \end{macrocode}
%    Here |\cb@pagecount| seems correct. Check if there is a page jump.
%    \begin{macrocode}
      \if@twocolumn
        \if@firstcolumn
          \@whilenum\cb@pagecount>\cb@nextpagejump\do{%
            \expandafter\cb@poppagejump\cb@pagejumplst\relax}%
          \ifnum\cb@pagecount=\cb@nextpagejump
            \cb@trace{Page jump: \string\cb@pagecount=\the\cb@pagecount}
            \global\advance\cb@pagecount by\tw@
            \global\@cb@pagejumptrue
          \else
            \global\@cb@pagejumpfalse
          \fi
        \else
%    \end{macrocode}
%    In the righthand column check the flag (see above). If set, write a
%    pagejump, but compensate for the increase done in the lefthand column.
%    \begin{macrocode}
          \if@cb@pagejump
            \cb@writepagejump{-3}%
          \fi
        \fi
      \fi
    \else
%    \end{macrocode}
%    Here |\cb@pagecount| is incorrect.
%    \begin{macrocode}
      \if@twocolumn
        \if@firstcolumn
          \global\advance\cb@pagecount by\tw@
          \global\@cb@pagejumpfalse
        \else
          \if@cb@pagejump
            \cb@trace{Page jump annulled, %
                      \string\cb@pagecount=\the\cb@pagecount}
          \else
            \cb@writepagejump{-1}%
            \global\advance\cb@pagecount by\tw@
            \cb@rerun
          \fi
        \fi
      \else
        \global\advance\cb@pagecount by\tw@
      \fi
    \fi
  \fi
}    
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@makecol}
% \begin{macro}{\@vtryfc}
%
%    These internal \LaTeX\ macros are modified in order to end the
%    changebars spanning the current page break (if any) and restart
%    them on the next page. The modifications are needed to reset the
%    special points for this page and add begin bars to top of box255.
%    The bars carried over from the previous page, and hence to be
%    restarted on this page, have been saved on the stack
%    |\cb@beginstack|. This stack is used to define new starting
%    points for the change bars, which are added to thetop of box
%    |\@cclv|.  Then the stack |\cb@endstack| is built and 
%    processed by |\cb@processActive|. Finally the original
%    |\@makecol| (saved as |\cb@makecol|) is executed.
%
% \changes{3.2}{1994/04/21}{Added setting of \cs{boxmaxdepth}}
% \changes{v3.3a}{1997/09/26}{Let \cs{cb@writeAux} be \cs{@gobble} to
%    prevent extra entries in the \file{.aux} file}
% \changes{v3.3a}{1997/09/26}{Now use the command
%    \cs{cb@startSpanBars} to define top points for bars spoanning a
%    page break} 
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    \begin{macrocode}
\let\ltx@makecol\@makecol
\def\cb@makecol{%
  \if@twocolumn
    \cb@trace{Twocolumn: \if@firstcolumn Left \else Right \fi column}%
  \fi
  \cb@trace@stack{before makecol, page \the\c@page,
                  \string\cb@pagecount=\the\cb@pagecount}%
  \let\cb@writeAux\@gobble
%    \end{macrocode}
%    First make sure that |\cb@pagecount| is correct.
%    Then add the necessary bar points at beginning and end.
%    \begin{macrocode}
  \cb@checkpagecount
  \setbox\@cclv \vbox{%
    \cb@resetpoints
    \cb@startSpanBars
    \unvbox\@cclv
    \boxmaxdepth\maxdepth}%
  \global\advance\cb@pagecount by\@ne
  \cb@buildstack\cb@processActive
  \ltx@makecol
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    In twocolumn pages write information to the aux file to indicate which
%    column we are in. This write must precede the whole column, including
%    floats. Therefore we insert it in the front of |\@outputbox|.
%    \begin{macrocode}
   \if@twocolumn
     \global\setbox\@outputbox \vbox to\@colht {%
       \if@firstcolumn\write\@auxout{\string\@cb@firstcolumntrue}%
       \else\write\@auxout{\string\@cb@firstcolumnfalse}%
       \fi
       \dimen@ \dp\@outputbox
       \unvbox \@outputbox
       \vskip -\dimen@
       }%
   \fi
  \cb@trace@stack{after makecol, page \the\c@page,
                  \string\cb@pagecount=\the\cb@pagecount}%
  }
\let\@makecol\cb@makecol
%    \end{macrocode}
%   When \LaTeX\ makes a page with only floats it doesn't use
%   |\@makecol|; instead it calls |\@vtryfc|, so we have to modify
%   this macro as well.
% \changes{v3.3a}{1997/09/26}{Let \cs{cb@writeAux} be \cs{@gobble} to
%    prevent extra entries in the \file{.aux} file}
% \changes{v3.3a}{1997/09/26}{Now use the command
%    \cs{cb@startSpanBars} to define top points for bars spoanning a
%    page break} 
% \changes{v3.5a}{2005/05/23}{We don't want spanning changebars from a
%    previous page in a float column.
%    The original code didn't work anyway. It did set \@outputbox,
%    which is immediately discarded in \cs{@ltx@vtryfc}.}
%    In twocolumn mode we must write either \cs{@cb@firstcolumntrue} or
%    \cs{@cb@firstcolumnfalse} to the \file{.aux} file.
%    \begin{macrocode}
\let\ltx@vtryfc\@vtryfc
\def\cb@vtryfc#1{%
  \cb@trace{In vtryfc, page \the\c@page,
                  \string\cb@pagecount=\the\cb@pagecount}%
  \let\cb@writeAux\@gobble
%    \end{macrocode}
%    First make sure that |\cb@pagecount| is correct.
%    Then generate a |\@cb@firstcolumntrue| or |\@cb@firstcolumnfalse| in
%    twocolumn mode.
%    \begin{macrocode}
  \cb@checkpagecount
  \ltx@vtryfc{#1}%
  \if@twocolumn
    \global\setbox\@outputbox \vbox to\@colht{%
      \if@firstcolumn\write\@auxout{\string\@cb@firstcolumntrue}%
      \else\write\@auxout{\string\@cb@firstcolumnfalse}%
      \fi
      \unvbox\@outputbox
      \boxmaxdepth\maxdepth
    }%
  \fi
  \global\advance\cb@pagecount by \@ne
}
\let\@vtryfc\cb@vtryfc
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\cb@processActive}
%
%    This macro processes each element on span stack. Each element
%    represents a bar that crosses the page break. There could be more
%    than one if bars are nested. It works as follows:
%
% \begin{verbatim}
%    pop top element of span stack
%    if point null (i.e., stack empty) then done
%    else
%      do an end bar on box255
%      save start for new bar at top of next page in \cb@startSaves
%      push active point back onto history stack (need to reprocess
%         on next page).
% \end{verbatim}
%
%    \begin{macrocode}
\def\cb@processActive{%
  \cb@pop\cb@endstack
  \ifnum\cb@topleft=\cb@nil
  \else
    \setbox\@cclv\vbox{%
      \unvbox\@cclv
      \boxmaxdepth\maxdepth
      \advance\cb@pagecount by -1\relax
      \cb@setEndPoints}%
    \cb@push\cb@historystack
%    \end{macrocode}
%    
% \changes{v3.3a}{1997/09/26}{Now also push points on (new)
%    \cs{cb@beginstack}}
%    \begin{macrocode}
    \cb@push\cb@beginstack
    \expandafter\cb@processActive
  \fi}
%    \end{macrocode}
% \end{macro}
%
% \changes{v3.3a}{1997/09/26}{Removed \cs{cb@saveBeginPoints}}
%
%  \begin{macro}{\cb@startSpanBars}
% \changes{v3.3a}{1997/09/26}{New macro}
%    This macro defines new points for each bar that was pushed on the
%    |\cb@beginstack|. Afterwards |\cb@beginstack| is empty.
% \changes{v3.3g}{1999/06/11}{Added stack tracing; no longer push
%    points on \cs{cb@currenstack}}
%    \begin{macrocode}
\def\cb@startSpanBars{%
  \cb@pop\cb@beginstack
  \ifnum\cb@topleft=\cb@nil
  \else
    \cb@setBeginPoints
    \cb@trace@stack{after StartSpanBars, page \the\c@page}%
    \expandafter\cb@startSpanBars
  \fi
  }
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\cb@buildstack}
% \begin{macro}{\cb@endstack}
%
%    The macro |\cb@buildstack| initializes the stack with open bars
%    and starts populating it.
%    \begin{macrocode}
\def\cb@buildstack{%
  \cb@initstack\cb@endstack
  \cb@pushNextActive}
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\cb@pushNextActive}
%    This macro pops the top element off the history stack
%    (|\cb@historystack|).  If the top left point is on a future page,
%    it is pushed back onto the history stack and processing stops.
%    If the point on the current or a previous page and it has an odd
%    number, the point is pushed on the stack with end points
%    |\cb@endstack|); if the point has an even number, it is popped
%    off the stack with end points since the bar to which it belongs
%    has terminated on the current page. 
%    \begin{macrocode}
\def\cb@pushNextActive{%
  \cb@pop\cb@historystack
  \ifnum\cb@topleft=\cb@nil
  \else
    \ifnum\cb@page>\cb@pagecount
      \cb@push\cb@historystack
    \else
      \ifodd\cb@topleft
        \cb@push\cb@endstack
      \else
        \cb@pop\cb@endstack
      \fi
      \expandafter\expandafter\expandafter\cb@pushNextActive
    \fi
  \fi}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Macros For Managing The Stacks of Bar points}
%
%    The macros make use of four stacks corresponding to |\special|
%    defpoints.  Each stack takes the form \texttt{<element>
%    ... <element>}
%
%    Each element is of the form \texttt{xxxnyyypzzzl} where
%    \texttt{xxx} is the number of the special point, \texttt{yyy} is
%    the page on which this point is set, and \texttt{zzz} is the
%    dimension used when connecting this point.
%
%    The stack |\cb@historystack| is built from the log information
%    and initially lists all the points.  As pages are processed,
%    points are popped off the stack and discarded.
%
%    The stack |\cb@endstack| and |\cb@beginstack| are two temporary
%    stacks used by the output routine and contain the stack with
%    definitions for of all bars crossing the current pagebreak (there
%    may be more than one with nested bars). 
%    They are built by popping elements off the history stack.
%
%    The stack |\cb@currentstack| contains all the current bars.
%    A |\cb@start| pushes an element onto this stack.
%    A |\cb@end| pops the top element off the stack and uses the
%    info to terminate the bar.
%
%    For performance and memory reasons, the history stack, which can
%    be very long, is special cased and a file is used to store this
%    stack rather than an internal macro.  The ``external'' interface
%    to this stack is identical to what is described above.  However,
%    when the history stack is popped, a line from the file is first
%    read and appended to the macro |\cb@historystack|.
%
% \begin{macro}{\cb@initstack}
%    A macro to (globally) initialize a stack.
%    \begin{macrocode}
\def\cb@initstack#1{\xdef#1{}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@historystack}
% \begin{macro}{\cb@write}
% \begin{macro}{\cb@read}
%    We need to initialise a stack to store the entries read from the
%    external history file.
%    \begin{macrocode}
\cb@initstack\cb@historystack
%    \end{macrocode}
%    We also need to allocate a read and a write stream for the
%    history file.
%    \begin{macrocode}
\newwrite\cb@write
\newread\cb@read
%    \end{macrocode}
%    And we open the history file for writing (which is done when the
%    \file{.aux} file is read in).
%    \begin{macrocode}
\immediate\openout\cb@write=\jobname.cb\relax
%    \end{macrocode}
% \end{macro}
% \end{macro}
% \end{macro}
%
% \begin{macro}{\cb@endstack}
% \begin{macro}{\cb@beginstack}
%    Allocate two stacks for the bars that span the current page break.
%    \begin{macrocode}
\cb@initstack\cb@endstack
\cb@initstack\cb@beginstack
%    \end{macrocode}
% \end{macro}
% \end{macro}
%
%  \begin{macro}{\cb@tempstack}
%    Allocate a stack for temporary storage
%    \begin{macrocode}
\cb@initstack\cb@tempstack
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\cb@currentstack}
%    And we allocate an extra stack that is needed to implement nesting
%    without having to rely on \TeX's grouping mechanism.
%    \begin{macrocode}
\cb@initstack\cb@currentstack
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@pop}
%
%    This macro pops the top element off the named stack and puts the
%    point value into |\cb@topleft|, the page value into |\cb@page|
%    and the bar width into |\cb@curbarwd|. If the stack is empty, it
%    returns a void value (|\cb@nil|) in |\cb@topleft| and sets
%    |\cb@page=0|.
%
% \changes{v3.4b}{2001/08/27}{Use global assignments, added more stack
%    tracing info}
%  \changes{v3.5a}{2005/05/23}{The check for history stack is improved.
%    Originally it succeeded if the stack contents was equal to the history
%    stack; now it specifically checks that we are popping the history
%    stack itself. Moreover we read from file only if the history
%    stack is empty.}
%    \begin{macrocode}
\def\cb@thehistorystack{\cb@historystack}
\def\cb@pop#1{%
  \ifx #1\@empty
    \def\cb@temp{#1}%
    \ifx\cb@temp\cb@thehistorystack
      \ifeof\cb@read
      \else
        {\endlinechar=-1\read\cb@read to\cb@temp
         \xdef\cb@historystack{\cb@historystack\cb@temp}%
        }%
      \fi
    \fi
  \fi
  \ifx#1\@empty
    \global\cb@topleft\cb@nil
    \global\cb@page\z@\relax
  \else
    \expandafter\cb@carcdr#1e#1%
  \fi
  \cb@trace@pop{#1}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@carcdr}
%    This macro is used to `decode' a stack entry.
% \changes{v3.3a}{1997/09/26}{No longer use \cs{@tempdima}}
% \changes{v3.4b}{2001/08/27}{Use global assignments}
%    \begin{macrocode}
\def\cb@carcdr#1n#2p#3l#4e#5{%
  \global\cb@topleft#1\relax
  \global\cb@page#2\relax
  \global\cb@curbarwd#3\relax
  \xdef#5{#4}}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@push}
%
%    The macro |\cb@push| Pushes |\cb@topleft|, |\cb@page| and
%    |\cb@curbarwd| onto the top of the named stack.
%
% \changes{v3.4b}{2001/08/27}{Added more stack tracing info}
%    \begin{macrocode}
\def\cb@push#1{%
  \xdef#1{\the\cb@topleft n\the\cb@page p\the\cb@curbarwd l#1}%
  \cb@trace@push{#1}}

%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@barpoint}
%    The macro |\cb@barpoint| populates the history file.  It writes
%    one line to \file{.cb} file which is equivalent to one
%    \meta{element} described above. 
% \changes{v3.5a}{2005/05/23}{Changes for twocolumn support: if a bar point
%    is in the left column we have to subtract one from the pagecount.}
%    \begin{macrocode}
\def\cb@barpoint#1#2#3{\cb@cnta=#2
  \if@cb@firstcolumn\advance\cb@cnta by\m@ne\fi
  \immediate\write\cb@write{#1n\the\cb@cnta p#3l}}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Macros For Checking That The \file{.aux} File Is Stable}
%
% \begin{macro}{\AtBeginDocument}
%
%    While reading the \file{.aux} file, \LaTeX{} has created the
%    history stack in a separate file. We need to close that file and
%    open it for reading. Also the `initialisation' of the
%    |\special| commands has to take place.  While we are
%    modifying the macro we also include the computation of the
%    possible positions of the changebars
%
%    For these actions we need to add to the \LaTeX\ begin-document
%    hook.
% \changes{3.2}{1994/04/21}{Use the \cs{AtBeginDocument} instead of
%    redefining \cs{document}}
%    \begin{macrocode}
\AtBeginDocument{%
  \cb@setup@specials
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    Add a sentinel to \cs{cb@pagejumplst}.
%    \begin{macrocode}
  \cb@pagejump{999999999,}%
%    \end{macrocode}
% \changes{v3.5a}{2005/05/23}{Adaption of \cs{cb@pagecount} is no longer
%    necessary, as \cs{cb@pagecount} will be adjusted at the beginning of
%    \cs{@makecol} and \cs{@vtryfc}.}
%    Compute the left and right positions of the changebars.
% \changes{v3.4g}{2004/01/09}{Added tracing information for the left
%    and right postions} 
%    \begin{macrocode}
  \cb@positions
  \cb@trace{%
    Odd left : \the\cb@odd@left\space
    Odd right : \the\cb@odd@right\MessageBreak
    Even left: \the\cb@even@left\space
    Even right: \the\cb@even@right
    }%
  \immediate\closeout\cb@write
  \immediate\openin\cb@read=\jobname.cb}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\AtEndDocument}
%    We need to issue a |\clearpage| to flush rest of document.  (Note
%    that I believe there is contention in this area: are there in
%    fact situations in which the end-document hooks need to be called
%    \emph{before} the final |\clearpage|? --- the documentation of
%    \LaTeX\ itself implies that there are.)  Then closes the \file{.cb}
%    file and reopens it for checking.  Initialize history stack (to
%    be read from file).  Let |\cb@barpoint=\cb@checkHistory| for
%    checking. 
% \changes{3.2}{1994/04/21}{Use \cs{AtEndDocument} now instead of
%    redefining \cs{enddocument}}
%
%    \begin{macrocode}
\AtEndDocument{%
  \clearpage
  \cb@initstack\cb@historystack
  \immediate\closein\cb@read
  \immediate\openin\cb@read=\jobname.cb%
%    \end{macrocode}
%    
% \changes{v3.5a}{2005/05/23}{For pdftex we also close and reread the
%    \file{.cb2} file.}
%    Let |\cb@pdfxy=\cb@checkPdfxy| for checking. Make |\cb@pagejump| dummy.
%    \begin{macrocode}
  \ifx\cb@readxy\@undefined
  \else
    \immediate\closein\cb@readxy
    \immediate\openin\cb@readxy=\jobname.cb2%
    \def\cb@pdfpoints{}%
    \def\cb@pdfpagenr{0}%
  \fi
  \@cb@firstcolumnfalse
  \cb@checkrerun
  \let\cb@pdfxy\cb@checkPdfxy
  \let\cb@pagejump\@gobble
  \let\cb@barpoint\cb@checkHistory}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@checkHistory}
%
%    Pops the top of the history stack (|\jobname.cb|) and checks to
%    see if the point and page numbers are the same as the arguments
%    $\#1$ and $\#2$ respectively.  Prints a warning message if
%    different.
% \changes{v3.5a}{2005/05/23}{Changes for twocolumn support: if a bar point
%    is in the left column we have to subtract one from the pagecount.}
%    \begin{macrocode}
\def\cb@checkHistory#1#2#3{%
  \cb@pop\cb@historystack
  \ifnum #1=\cb@topleft\relax
    \cb@cnta=#2
    \if@cb@firstcolumn\advance\cb@cnta by\m@ne\fi
    \ifnum \cb@cnta=\cb@page\relax
%    \end{macrocode}
%    Both page and point numbers are equal; do nothing,
%    \begin{macrocode}
    \else
%    \end{macrocode}
%    but generate a warning when page numbers don't match, or
%    \begin{macrocode}
      \cb@error
    \fi
  \else
%    \end{macrocode}
%    when point numbers don't match.
%    \begin{macrocode}
    \cb@error
  \fi}
%    \end{macrocode}
%    Dummy definition for |\cb@checkPdfxy|. This will be overwritten by
%    the \Lopt{pdftex}\cbstart{} and \Lopt{xetex}\cbend{} options.
%    \begin{macrocode}
\def\cb@checkPdfxy#1#2#3#4#5{}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@rerun}
% \changes{v3.5a}{2005/05/23}{Changes for better twocolumn support}
%    The macro |\cb@rerun| is called when we detect that we need to rerun
%    \LaTeX. 
%    \begin{macrocode}
\def\cb@rerun{%
  \global\let\cb@checkrerun\cb@error}
\let\cb@checkrerun\relax
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\cb@error}
%    When a mismatch between the changebar information in the
%    auxiliary file and the history stack is detected a warning is
%    issued; further checking is disabled.
% \changes{v3.5a}{2005/05/23}{Added pdftex support}
%    For pdf\TeX\cbstart{} and Xe\TeX\cbend{} we also disable
%    |\cb@checkPdfxy|.
%    \begin{macrocode}
\def\cb@error{%
  \PackageWarning{Changebar}%
    {Changebar info has changed.\MessageBreak
     Rerun to get the bars right}
  \gdef\cb@checkHistory##1##2##3{}%
  \let\cb@barpoint\cb@checkHistory
  \gdef\cb@checkPdfxy##1##2##3##4##5{}%
  \let\cb@pdfxy\cb@checkPdfxy}
%    \end{macrocode}
% \end{macro}
%
% \subsection{Macros For Making It Work With Nested Floats/Footnotes}
%
% \begin{macro}{\end@float}
%    This is a replacement for the \LaTeX-macro of the same name.  All
%    it does is check to see if changebars are active and, if so, it
%    puts changebars around the box containing the float.  Then it
%    calls the original \LaTeX\ |\end@float|.
%
%    \begin{macrocode}
\let\ltx@end@float\end@float
%    \end{macrocode}
% \changes{v3.3g}{1999/06/11}{Added stack tracing}
% \changes{v3.4b}{2001/08/27}{Call \cs{@endfloatbox} en use
%    \cs{color@vbox} to take the extra box and group for color into
%    account}
%    \begin{macrocode}
\def\cb@end@float{%
  \cb@trace@stack{end float on page \the\c@page}%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
  \else
    \cb@push\cb@currentstack
    \global\cb@curbarwd=\cb@curbarwd
    \@endfloatbox
    \global\setbox\@currbox
      \color@vbox
      \normalcolor
      \vbox\bgroup\cb@start[\cb@curbarwd]\unvbox\@currbox\cb@end
  \fi
  \ltx@end@float}
\let\end@float\cb@end@float
%    \end{macrocode}
%    This only works if this new version of |\end@float| is really
%    used. With \LaTeX2.09 the documentstyles used to contain:
% \begin{verbatim}
%    \let\endfigure\end@float
% \end{verbatim}
%    In that case this binding has to be repeated after the
%    redefinition of |\end@float|. However, the \LaTeXe\ class files
%    use |\newenvironment| to define the \Lenv{figure} and
%    \Lenv{table} environments. In that case there is no need to
%    rebind |\endfigure|.
% \changes{3.2}{1994/04/21}{Removed
%    \cs{let}\cs{endfigure}\cs{end@float}, no longer necessary}
%
%  \begin{macro}{\@xympar}
%    There is one snag with this redefinition in that the macro
%    |\end@float| is also used by the command |\marginpar|. This may
%    lead to problems with stack underflow. Therefore we need to
%    redefine an internal macro from the marginal paragraph mechanism
%    as well. The solution is to make sure the this macro uses the
%    original definition of |\end@float|.
% \changes{v3.5d}{2005/12/24}{Redefine \cs{@xympar} to use the
%    original version of \cs{end@float}}
%    \begin{macrocode}
\let\ltx@@xympar\@xympar
\def\@xympar{%
  \let\end@float\ltx@end@float
  \ltx@@xympar
  \let\end@float\cb@end@float}
%    \end{macrocode}
%  \end{macro}
%
% \end{macro}
%
%  \begin{macro}{\float@end}
%    When the \pkg{float} package is being used we need to take care
%    of its changes to the float mechanism. It defines it's own macros
%    (|\float@end| and |\float@dblend| which need to be modified for
%    changebars to work.
%
%    First we'll save the original as |\flt@float@end|.
%    \begin{macrocode}
\let\flt@float@end\float@end
%    \end{macrocode}
%    Then we redefine it to insert the changebarcode.
%    \begin{macrocode}
\def\float@end{%
  \cb@trace@stack{end float on page \the\c@page}%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
  \else
    \cb@push\cb@currentstack
    \global\cb@curbarwd\cb@curbarwd
    \@endfloatbox
    \global\setbox\@currbox
      \color@vbox
      \normalcolor
      \vbox\bgroup\cb@start[\cb@curbarwd]\unvbox\@currbox\cb@end
  \fi
  \let\end@float\ltx@end@float
  \flt@float@end
  }
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\end@dblfloat}
%    This is a replacement for the \LaTeX-macro of the same name.  All
%    it does is check to see if changebars are active and, if so, it
%    puts changebars around the box containing the float. In this case
%    the \LaTeX\ macro had to be rewritten.
%
% \changes{v3.4e}{2001/09/07}{Double column floats only carry a
%    changebar with an appropriate change of \cs{end@dblfloat}}
%    \begin{macrocode}
\let\ltx@end@dblfloat\end@dblfloat
\def\cb@end@dblfloat{%
  \if@twocolumn
    \cb@trace@stack{end dblfloat on page \the\c@page}%
    \cb@pop\cb@currentstack
    \ifnum\cb@topleft=\cb@nil
    \else
      \cb@push\cb@currentstack
      \global\cb@curbarwd=\cb@curbarwd
      \@endfloatbox
      \global\setbox\@currbox
        \color@vbox
        \normalcolor
        \vbox\bgroup\cb@start[\cb@curbarwd]\unvbox\@currbox\cb@end
    \fi
    \@endfloatbox
    \ifnum\@floatpenalty <\z@
      \@largefloatcheck
      \@cons\@dbldeferlist\@currbox
    \fi
    \ifnum \@floatpenalty =-\@Mii \@Esphack\fi
  \else
    \end@float
  \fi}
\let\end@dblfloat\cb@end@dblfloat
%    \end{macrocode}
% \end{macro}
%
%  \begin{macro}{\float@dblend}
%    Something similar needs to be done for the case where the
%    \pkg{float} package is being used...
%    \begin{macrocode}
\let\flt@float@dblend\float@dblend
\def\float@dblend{%
  \cb@trace@stack{end dbl float on page \the\c@page}%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
  \else
    \cb@push\cb@currentstack
    \global\cb@curbarwd=\cb@curbarwd
    \@endfloatbox
    \global\setbox\@currbox
      \color@vbox
      \normalcolor
      \vbox\bgroup\cb@start[\cb@curbarwd]\unvbox\@currbox\cb@end
  \fi
  \let\end@dblfloat\ltx@end@dblfloat
  \flt@float@dblend
  }
%    \end{macrocode}
%  \end{macro}
%
% \begin{macro}{\@footnotetext}
%    This is a replacement for the \LaTeX\ macro of the same name.
%    It simply checks to see if changebars are active, and if so,
%    wraps the macro argument (i.e., the footnote) in changebars.
%
% \changes{3.1b}{1993/10/11}{Added missing percent sign to prevent
%    spurious white space in the output.}
%    \begin{macrocode}
\let\ltx@footnotetext\@footnotetext
%    \end{macrocode}
% \changes{v3.3g}{1999/06/11}{Added stack tracing}
%    \begin{macrocode}
\long\def\cb@footnotetext#1{%
  \cb@trace@stack{end footnote on page \the\c@page}%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
    \ltx@footnotetext{#1}%
  \else
    \cb@push\cb@currentstack
    \edef\cb@temp{\the\cb@curbarwd}%
    \ltx@footnotetext{\cb@start[\cb@temp]#1\cb@end}%
  \fi}
\let\@footnotetext\cb@footnotetext
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@mpfootnotetext}
%
%    Replacement for the \LaTeX\ macro of the same name.  Same thing
%    as |\@footnotetext|.
%
% \changes{3.1b}{1993/10/11}{Added missing percent sign to prevent
%    spurious white space in the output.}
%    \begin{macrocode}
\let\ltx@mpfootnotetext\@mpfootnotetext
%    \end{macrocode}
%    \begin{macrocode}
\long\def\cb@mpfootnotetext#1{%
  \cb@pop\cb@currentstack
  \ifnum\cb@topleft=\cb@nil
    \ltx@mpfootnotetext{#1}%
  \else
    \cb@push\cb@currentstack
    \edef\cb@temp{\the\cb@curbarwd}%
    \ltx@mpfootnotetext{\cb@start[\cb@temp]#1\cb@end}%
  \fi}
\let\@mpfootnotetext\cb@mpfootnotetext
%</package>
%    \end{macrocode}
% \end{macro}
%
% 
% \Finale
%
\endinput
%% \CharacterTable
%%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%%   Digits        \0\1\2\3\4\5\6\7\8\9
%%   Exclamation   \!     Double quote  \"     Hash (number) \#
%%   Dollar        \$     Percent       \%     Ampersand     \&
%%   Acute accent  \'     Left paren    \(     Right paren   \)
%%   Asterisk      \*     Plus          \+     Comma         \,
%%   Minus         \-     Point         \.     Solidus       \/
%%   Colon         \:     Semicolon     \;     Less than     \<
%%   Equals        \=     Greater than  \>     Question mark \?
%%   Commercial at \@     Left bracket  \[     Backslash     \\
%%   Right bracket \]     Circumflex    \^     Underscore    \_
%%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%%   Right brace   \}     Tilde         \~}
%%
%%