summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/bibtex/bst/beebe/xbtxbst.doc
blob: 05b733c0995d6a067be4d8b975c0c4359ecc07e4 (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
% /u/sy/beebe/tex/bib/merge/xbtxbst.doc, Thu Sep 12 10:19:13 1991
% Edit by Nelson H. F. Beebe <beebe@magna.math.utah.edu>
% /u/sy/beebe/tex/bib/merge/xbtxbst.doc, Wed Oct 17 08:27:24 1990
% Edit by Nelson H.F. Beebe <beebe@sandy.math.utah.edu>

% NB: Important convention: comment lines beginning with 2 (or
%     more) percents are to be preserved in the derived style
%     files.   Comment lines beginning with only 1 percent can be
%     discarded (and are, if the derived files are produced with
%     the UNIX Makefile that accompanies this file.)

%% =====================================================================
%%  @BibTeX-style-file{
%%      author          = "Nelson H. F. Beebe",
%%      version         = "1.02",
%%      date            = "12 September 1991",
%%      filename        = "xbtxbst.doc",
%%      address         = "Center for Scientific Computing
%%                         Department of Mathematics
%%                         South Physics Building
%%                         University of Utah
%%                         Salt Lake City, UT 84112
%%                         USA
%%                         Tel: (801) 581-5254",
%%      checksum        = "50938 2665 11236 78415",
%%      email           = "beebe@math.utah.edu (Internet)",
%%      codetable       = "ISO/ASCII",
%%      keywords        = "BibTeX, style, bibliography",
%%      supported       = "yes",
%%      docstring       = "This file is a modification of the standard
%%                         BibTeX btxbst.doc file, or is a .bst file
%%                         derived from that modification.  It contains
%%                         added support for ISBN and ISSN fields, as
%%                         well as for the PERIODICAL entry.  The UNIX C
%%                         preprocessor can be used to extract the
%%                         extensions of the standard styles, as
%%                         follows:
%%
%%                         cpp -P -DPLAIN xbtxbst.doc is-plain.txt
%%                         cpp -P -DUNSRT xbtxbst.doc is-unsrt.txt
%%                         cpp -P -DALPHA xbtxbst.doc is-alpha.txt
%%                         cpp -P -DABBRV xbtxbst.doc is-abbrv.txt
%%
%%                         If desired, a sed script can be used to
%%                         eliminate non-essential comments (this
%%                         reduces the file size by 2/3); a command
%%                         filter step like
%%                                 sed -e '/^%$/d' -e '/^%[^%].*$/d'
%%                         will accomplish that job.
%%
%%                         The checksum field above contains a CRC-16
%%                         checksum as the first value, followed by the
%%                         equivalent of the standard UNIX wc (word
%%                         count) utility output of lines, words, and
%%                         characters.  This is produced by Robert
%%                         Solovay's checksum utility."
%%      }
%% =====================================================================
%% Revision history (reverse time order):
%% 1.02 [12-Sep-1991]
%%      Merge in Barbara N. Beeton's suggestion for hyphen-less
%%      line breaks around volume(number):page.
%% 1.01 [10-Sep-1991]
%%      Update file comment header and use Solovay checksum program.
%% 1.00 [17-Oct-1990]
%%      Original version merging hand-edits of is-xxx.bst files into
%%      this master file, xbtxbst.doc.

% In the following, only essential changes have been applied; the
% documentation immediately below referring to the use of cpp on
% btxbst.doc has not been altered.  See the docstring entry above
% for current information.

%% BibTeX `plain' family
%%       version 0.99b for BibTeX versions 0.99a or later, LaTeX version 2.09.
%%       Copyright (C) 1985, all rights reserved.
%%       Copying of this file is authorized only if either
%%       (1) you make absolutely no changes to your copy, including name, or
%%       (2) if you do make changes, you name it something other than
%%       btxbst.doc, plain.bst, unsrt.bst, alpha.bst, and abbrv.bst.
%%       This restriction helps ensure that all standard styles are identical.
%%       The file btxbst.doc has the documentation for this style.
%
% Please notify Oren Patashnik (PATASHNIK@SCORE.STANFORD.EDU) of any bugs in
% these standard styles or in this documentation file.
%
% This is file btxbxt.doc; it helps document bibliography styles,
% and is also a template file that you can use to make
% several different style files, if you have access to a C preprocessor.
% For example, the standard styles were made by doing something like
%       cpp -P -DPLAIN btxbst.doc plain.txt
%       cpp -P -DUNSRT btxbst.doc unsrt.txt
%       cpp -P -DALPHA btxbst.doc alpha.txt
%       cpp -P -DABBRV btxbst.doc abbrv.txt
% and then renaming after removing unwanted comments and blank lines.
% If you don't have access,
% you can edit this file by hand to imitate the preprocessor,
% with the following explanation of the C preprocessor constructs used here.
%
% The output of the preprocessor is the same as the input, except that certain
% lines will be excluded (and some blank lines will be added).  The sequence
%       #if VAR
%           lines to be included when VAR is not zero
%       #else
%           lines to be included when VAR is zero
%       #endif
% (with the #-signs appearing in column 1) means that one set or the other of
% the lines are to be included depending on the value of VAR.
% The #else part is optional.  Comments can be added after #else and #endif.
% Variables can be set by
%       #define VAR value
% and one can also use #ifdef VAR to see if VAR has any value, and #ifndef
% to see if it has none.
% Another #if form used in this file is #if !VAR, which includes the lines
% after the #if only if VAR is zero.
%
% Convention: Use all uppercase identifiers for these preprocessor variables
% so you can spot them easily
%
% The command line to the preprocessor should define one of PLAIN, UNSRT, ALPHA
% or ABBRV (though PLAIN will be used by default if none is given),
% and the following lines will set various boolean variables to control the
% various lines that are chosen from the rest of the file.
% Each boolean variable should be set true (1) or false (0) in each style.
% Here are the current variables, and their meanings:
%       LAB_ALPH:       an alphabetic label is used (if false then a numeric
%                           label is used)
%       SORTED:         the entries should be sorted by label (if nonnumeric)
%                           and other info, like authors (if false, then
%                           entries remain in order of occurrence)
%       NAME_FULL:      the authors, editors, etc., get the full names as
%                           given in the bibliography file (if false, the first
%                           names become initials)
%       ATIT_LOWER:     titles of non-"books" (e.g., articles) should be
%                           converted to lower-case, except the first letter or
%                           first letter after a colon
%                           (if false then they appear as in the database)
%       MONTH_FULL:     months are spelled out in full (if false, then
%                           they're abbreviated)
%       JOUR_FULL:      macro journal names are spelled out in full
%                           (if false then they are abbreviated, currently
%                           as they appear in ACM publications)
#ifndef UNSRT
#   ifndef ALPHA
#       ifndef ABBRV
#           define PLAIN 1
#       endif
#   endif
#endif
#ifdef PLAIN
% plain style (sorted numbers)
#   define LAB_ALPH 0
#   define SORTED 1
#   define NAME_FULL 1
#   define ATIT_LOWER 1
#   define MONTH_FULL 1
#   define JOUR_FULL 1
#endif
#ifdef UNSRT
% unsrt style (unsorted numbers)
#   define LAB_ALPH 0
#   define SORTED 0
#   define NAME_FULL 1
#   define ATIT_LOWER 1
#   define MONTH_FULL 1
#   define JOUR_FULL 1
#endif
#ifdef ALPHA
% alpha style (sorted short alphabetics)
#   define LAB_ALPH 1
#   define SORTED 1
#   define NAME_FULL 1
#   define ATIT_LOWER 1
#   define MONTH_FULL 1
#   define JOUR_FULL 1
#endif
#ifdef ABBRV
% abbrv style (sorted numbers, with abbreviations)
#   define LAB_ALPH 0
#   define SORTED 1
#   define NAME_FULL 0
#   define ATIT_LOWER 1
#   define MONTH_FULL 0
#   define JOUR_FULL 0
#endif
%
%   Entry formatting: Similar to that recommended by Mary-Claire van Leunen
%       in "A Handbook for Scholars".  Book-like titles are italicized
%       (emphasized) and non-book titles are converted to sentence
%       capitilization (and not enclosed in quotes).
%       This file outputs a \newblock between major blocks of an entry
%       (the name \newblock is analogous to the names \newline and \newpage)
%       so that the user can obtain an "open" format, which has a line break
%       before each block and lines after the first are indented within blocks,
%       by giving the optional \documentstyle argument `openbib';
%       The default is the "closed" format---blocks runs together.
%
%   Citation alphabetic label format:
%               [Knu73] for single author (or editor or key)
%               [AHU83] (first letters of last names) for multiple authors
%
%   Citation label numberic format:
%               [number]
%
%   Reference list ordering for sorted, alphabetic lables:
%               alphabetical by citation label, then by author(s) or whatever
%               passes for author in the absence of one, then by year,
%               then title
%
%   Reference list ordering for sorted, numeric lables:
%               alphabetical by author(s) or whatever passes
%               for author in the absence of one, then by year, then title
%
%   Reference list ordering for unsorted:
%               by the order cited in the text
%
%   History
%   12/16/84    (HWT)   Original `plain' version, by Howard Trickey.
%   12/23/84    (LL)    Some comments made by Leslie Lamport.
%    2/16/85    (OP)    Changes based on LL's comments, Oren Patashnik.
%    2/17/85    (HWT)   Template file and other standard styles made.
%    3/28/85    (OP)    First release, version 0.98b for BibTeX 0.98f.
%    5/ 9/85    (OP)    Version 0.98c for BibTeX 0.98i:
%                       fixed Theoretical Computer Science macro name;
%                       fixed the format.vol.num.pages function.
%    1/24/88    (OP)    Version 0.99a for BibTeX 0.99a, main changes:
%                       assignment operator (:=) arguments reversed;
%                       the preamble$ function outputs the database PREAMBLE;
%                       entry.max$ and global.max$ (built-in) variables replace
%                       entry.string.max and global.string.max functions;
%                       alphabetizing by year then title, not just title;
%                       many unnecessary ties removed; \it ==> \em;
%                       the `alpha' style uses a superscripted `+' instead of a
%                       `*' for unnamed names in constructing the label;
%                       the `abbrv' style now uses "Mar." and "Sept.";
%                       the functions calc.label and presort now look at just
%                       the fields they're supposed to;
%                       BOOKLET, MASTERSTHESIS, TECHREPORT use nonbook titles;
%                       INBOOK and INCOLLECTION take an optional type (e.g.
%                       type = "Section"), overriding the default "chapter";
%                       BOOK, INBOOK, INCOLLECTION, and PROCEEDINGS now allow
%                       either volume or number, not just volume;
%                       INCOLLECTION now allows an edition and series field;
%                       PROCEEDINGS and INPROCEEDINGS now use the address field
%                       to tell where a conference was held;
%                       INPROCEEDINGS and PROCEEDINGS now allow either volume
%                       or number, and also a series field;
%                       MASTERSTHESIS and PHDTHESIS accept types other than
%                       "Master's thesis" and "PhD thesis";
%                       UNPUBLISHED now outputs, in one block, note then date;
%                       MANUAL now prints out the organization in
%                       the first block if the author field is empty;
%                       MISC can't be empty---it requires some optional field.
%    3/23/88    (OP)    Version 0.99b for BibTeX 0.99c---changed the three
%                       erroneous occurrences of `cite ' to `cite$ '; this
%                       change didn't affect the four standard styles, so the
%                       0.99a versions of those styles are still current.
%
% The ENTRY declaration
%   Like Scribe's (according to pages 231-2 of the April '84 edition),
%   but no fullauthor or editors fields because BibTeX does name handling.
%   The annote field is commented out here because this family doesn't
%   include an annotated bibliography style.  And in addition to the fields
%   listed here, BibTeX has a built-in crossref field, explained later.

ENTRY
% Fields:
  { address
%           Usually the address of a publisher or other type of organization.
%           Put information in this field only if it helps the reader find the
%           thing---for example you should omit the address of a major
%           publisher entirely.  For a PROCEEDINGS or an INPROCEEDINGS,
%           however, it's the address of the conference; for those two entry
%           types, include the publisher's or organization's address, if
%           necessary, in the publisher or organization field.
%    annote
%           Long annotation---for annotated bibliographies (begins sentence).
    author
%           Name(s) of author(s), in BibTeX name format.
    booktitle
%           Book title when the thing being referenced isn't the whole book.
%           For book entries, the title field should be used instead.
    chapter
%           Chapter (or section or whatever) number.
    edition
%           Edition of a book---should be an ordinal (e.g., "Second").
    editor
%           Name(s) of editor(s), in BibTeX name format.
%           If there is also an author field, then the editor field should be
%           for the book or collection that the work appears in.
    howpublished
%            How something strange has been published (begins sentence).
    institution
%           Sponsoring institution of a technical report.
    isbn
%           ISBN book number (a 10-digit number with optional
%           embedded spaces or hyphens, where a `digit' is one of
%           0123456789X).
    issn
%           ISSN serial publication number (an 8-digit number with optional
%           embedded spaces or hyphens, where a `digit' is one of
%           0123456789X).
    journal
%           Journal name (macros are provided for many).
    key
%           Alphabetizing, labeling, and cross-referencing key
%           (needed when an entry has no author or editor).
    month
%           Month (macros are provided).
    note
%           To help the reader find a reference (begins sentence).
    number
%           Number of a journal or technical report, or of a work in a series.
    organization
%           Organization sponsoring a conference (or publishing a manual); if
%           the editor (or author) is empty, and if the organization produces
%           an awkward label or cross reference, you should put appropriately
%           condensed organization information in the key field as well.
    pages
%           Page number or numbers (use `--' to separate a range, use `+'
%           to indicate pages following that don't form a simple range).
    publisher
%           Publisher name.
    school
%           School name (for theses).
    series
%           The name of a series or set of books.
%           An individual book will will also have it's own title.
    title
%           The title of the thing you're referred to.
    type
%           Type of a Techreport (e.g., "Research Note") to be used instead of
%           the default "Technical Report"; or, similarly, the type of a
%           thesis; or of a part of a book.
    volume
%           The volume number of a journal or multivolume work.
    year
%           The year should contain only numerals (technically, it should end
%           with four numerals, after purification; doesn't a begin sentence).
  }
% There are no integer entry variables
  {}
% These string entry variables are used to form the citation label.
% In a storage pinch, sort.label can be easily computed on the fly.
#if LAB_ALPH
#if SORTED
  { label extra.label sort.label }
#else !SORTED
% It doesn't seem like a good idea to use an order-of-citation
% reference list when using alphabetic labels, but when this happens
% we do things a little differently
  { label }
#endif SORTED
#else !LAB_ALPH
  { label }
#endif LAB_ALPH

% Each entry function starts by calling output.bibitem, to write the
% \bibitem and its arguments to the .BBL file.  Then the various fields
% are formatted and printed by output or output.check.  Those functions
% handle the writing of separators (commas, periods, \newblock's),
% taking care not to do so when they are passed a null string.
% Finally, fin.entry is called to add the final period and finish the
% entry.
%
% A bibliographic reference is formatted into a number of `blocks':
% in the open format, a block begins on a new line and subsequent
% lines of the block are indented.  A block may contain more than
% one sentence (well, not a grammatical sentence, but something to
% be ended with a sentence ending period).  The entry functions should
% call new.block whenever a block other than the first is about to be
% started.  They should call new.sentence whenever a new sentence is
% to be started.  The output functions will ensure that if two
% new.sentence's occur without any non-null string being output between
% them then there won't be two periods output.  Similarly for two
% successive new.block's.
%
% The output routines don't write their argument immediately.
% Instead, by convention, that argument is saved on the stack to be
% output next time (when we'll know what separator needs to come
% after it).  Meanwhile, the output routine has to pop the pending
% output off the stack, append any needed separator, and write it.
%
% To tell which separator is needed, we maintain an output.state.
% It will be one of these values:
%       before.all              just after the \bibitem
%       mid.sentence            in the middle of a sentence: comma needed
%                                       if more sentence is output
%       after.sentence          just after a sentence: period needed
%       after.block             just after a block (and sentence):
%                                       period and \newblock needed.
% Note: These styles don't use after.sentence
%
% VAR: output.state : INTEGER           -- state variable for output
%
% The output.nonnull function saves its argument (assumed to be nonnull)
% on the stack, and writes the old saved value followed by any needed
% separator.  The ordering of the tests is decreasing frequency of
% occurrence.
%
% output.nonnull(s) ==
%  BEGIN
%       s := argument on stack
%       if output.state = mid.sentence then
%           write$(pop() * ", ")
%                 -- "pop" isn't a function: just use stack top
%       else
%           if output.state = after.block then
%               write$(add.period$(pop()))
%               newline$
%               write$("\newblock ")
%           else
%               if output.state = before.all then
%                   write$(pop())
%               else        -- output.state should be after.sentence
%                   write$(add.period$(pop()) * " ")
%               fi
%           fi
%           output.state := mid.sentence
%       fi
%       push s on stack
%  END
%
% The output function calls output.nonnull if its argument is non-empty;
% its argument may be a missing field (thus, not necessarily a string)
%
% output(s) ==
%  BEGIN
%       if not empty$(s) then output.nonnull(s)
%       fi
%  END
%
% The output.check function is the same as the output function except that, if
% necessary, output.check warns the user that the t field shouldn't be empty
% (this is because it probably won't be a good reference without the field;
% the entry functions try to make the formatting look reasonable even when
% such fields are empty).
%
% output.check(s,t) ==
%  BEGIN
%       if empty$(s) then
%           warning$("empty " * t * " in " * cite$)
%       else output.nonnull(s)
%       fi
%  END
%
% The output.bibitem function writes the \bibitem for the current entry
% (the label should already have been set up), and sets up the separator
% state for the output functions.  And, it leaves a string on the stack
% as per the output convention.
%
% output.bibitem ==
%  BEGIN
%       newline$
%       write$("\bibitem[")     % for alphabetic labels,
%       write$(label)           % these three lines
%       write$("]{")            % are used
%       write$("\bibitem{")             % this line for numeric labels
%       write$(cite$)
%       write$("}")
%       push "" on stack
%       output.state := before.all
%  END
%
% The fin.entry function finishes off an entry by adding a period to the
% string remaining on the stack.  If the state is still before.all
% then nothing was produced for this entry, so the result will look bad,
% but the user deserves it. (We don't omit the whole entry because the
% entry was cited, and a bibitem is needed to define the citation label.)
%
% fin.entry ==
%  BEGIN
%       write$(add.period$(pop()))
%       newline$
%  END
%
% The new.block function prepares for a new block to be output, and
% new.sentence prepares for a new sentence.
%
% new.block ==
%  BEGIN
%       if output.state <> before.all then
%           output.state := after.block
%       fi
%  END
%
% new.sentence ==
%  BEGIN
%       if output.state <> after.block then
%           if output.state <> before.all then
%               output.state :=  after.sentence
%           fi
%       fi
%  END
%

INTEGERS { output.state before.all mid.sentence after.sentence after.block }

FUNCTION {init.state.consts}
{ #0 'before.all :=
  #1 'mid.sentence :=
  #2 'after.sentence :=
  #3 'after.block :=
}

% the variables s and t are temporary string holders

STRINGS { s t }

FUNCTION {output.nonnull}
{ 's :=
  output.state mid.sentence =
    { ", " * write$ }
    { output.state after.block =
        { add.period$ write$
          newline$
          "\newblock " write$
        }
        { output.state before.all =
            'write$
            { add.period$ " " * write$ }
          if$
        }
      if$
      mid.sentence 'output.state :=
    }
  if$
  s
}

FUNCTION {output}
{ duplicate$ empty$
    'pop$
    'output.nonnull
  if$
}

FUNCTION {output.check}
{ 't :=
  duplicate$ empty$
    { pop$ "empty " t * " in " * cite$ * warning$ }
    'output.nonnull
  if$
}

FUNCTION {output.bibitem}
{ newline$
#if LAB_ALPH
  "\bibitem[" write$
  label write$
  "]{" write$
#else
  "\bibitem{" write$
#endif LAB_ALPH
  cite$ write$
  "}" write$
  newline$
  ""
  before.all 'output.state :=
}

% This function finishes all entries.

FUNCTION {fin.entry}
{ add.period$
  write$
  newline$
}

FUNCTION {new.block}
{ output.state before.all =
    'skip$
    { after.block 'output.state := }
  if$
}

FUNCTION {new.sentence}
{ output.state after.block =
    'skip$
    { output.state before.all =
        'skip$
        { after.sentence 'output.state := }
      if$
    }
  if$
}

% These three functions pop one or two (integer) arguments from the stack
% and push a single one, either 0 or 1.
% The 'skip$ in the `and' and `or' functions are used because
% the corresponding if$ would be idempotent

FUNCTION {not}
{   { #0 }
    { #1 }
  if$
}

FUNCTION {and}
{   'skip$
    { pop$ #0 }
  if$
}

FUNCTION {or}
{   { pop$ #1 }
    'skip$
  if$
}

% Sometimes we begin a new block only if the block will be big enough.  The
% new.block.checka function issues a new.block if its argument is nonempty;
% new.block.checkb does the same if either of its TWO arguments is nonempty.

FUNCTION {new.block.checka}
{ empty$
    'skip$
    'new.block
  if$
}

FUNCTION {new.block.checkb}
{ empty$
  swap$ empty$
  and
    'skip$
    'new.block
  if$
}

% The new.sentence.check functions are analogous.

FUNCTION {new.sentence.checka}
{ empty$
    'skip$
    'new.sentence
  if$
}

FUNCTION {new.sentence.checkb}
{ empty$
  swap$ empty$
  and
    'skip$
    'new.sentence
  if$
}

% Here are some functions for formatting chunks of an entry.
% By convention they either produce a string that can be followed by
% a comma or period (using add.period$, so it is OK to end in a period),
% or they produce the null string.
%
% A useful utility is the field.or.null function, which checks if the
% argument is the result of pushing a `missing' field (one for which no
% assignment was made when the current entry was read in from the database)
% or the result of pushing a string having no non-white-space characters.
% It returns the null string if so, otherwise it returns the field string.
% Its main (but not only) purpose is to guarantee that what's left on the
% stack is a string rather than a missing field.
%
% field.or.null(s) ==
%  BEGIN
%       if empty$(s) then return ""
%       else return s
%  END
%
% Another helper function is emphasize, which returns the argument emphazised,
% if that is non-empty, otherwise it returns the null string.  Italic
% corrections aren't used, so this function should be used when punctation
% will follow the result.
%
% emphasize(s) ==
%  BEGIN
%       if empty$(s) then return ""
%       else return "{\em " * s * "}"
%
% The format.names function formats the argument (which should be in
% BibTeX name format) into "First Von Last, Junior", separated by commas
% and with an "and" before the last (but ending with "et~al." if the last
% of multiple authors is "others").  This function's argument should always
% contain at least one name.
%
% VAR: nameptr, namesleft, numnames: INTEGER
% pseudoVAR: nameresult: STRING         (it's what's accumulated on the stack)
%
% format.names(s) ==
%  BEGIN
%       nameptr := 1
%       numnames := num.names$(s)
%       namesleft := numnames
%       while namesleft > 0
%         do
%                               % for full names:
%           t := format.name$(s, nameptr, "{ff~}{vv~}{ll}{, jj}")
%                               % for abbreviated first names:
%           t := format.name$(s, nameptr, "{f.~}{vv~}{ll}{, jj}")
%           if nameptr > 1 then
%               if namesleft > 1 then nameresult := nameresult * ", " * t
%               else if numnames > 2
%                      then nameresult := nameresult * ","
%                    fi
%                    if t = "others"
%                      then nameresult := nameresult * " et~al."
%                      else nameresult := nameresult * " and " * t
%                    fi
%               fi
%           else nameresult := t
%           fi
%           nameptr := nameptr + 1
%           namesleft := namesleft - 1
%         od
%       return nameresult
%  END
%
% The format.authors function returns the result of format.names(author)
% if the author is present, or else it returns the null string
%
% format.authors ==
%  BEGIN
%       if empty$(author) then return ""
%       else return format.names(author)
%       fi
%  END
%
% Format.editors is like format.authors, but it uses the editor field,
% and appends ", editor" or ", editors"
%
% format.editors ==
%  BEGIN
%       if empty$(editor) then return ""
%       else
%           if num.names$(editor) > 1 then
%               return format.names(editor) * ", editors"
%           else
%               return format.names(editor) * ", editor"
%           fi
%       fi
%  END
%
% Other formatting functions are similar, so no "comment version" will be
% given for them.
%
% The `pop$' in this function gets rid of the duplicate `empty' value and
% the `skip$' returns the duplicate field value

FUNCTION {field.or.null}
{ duplicate$ empty$
    { pop$ "" }
    'skip$
  if$
}

FUNCTION {emphasize}
{ duplicate$ empty$
    { pop$ "" }
    { "{\em " swap$ * "}" * }
  if$
}

INTEGERS { nameptr namesleft numnames }

FUNCTION {format.names}
{ 's :=
  #1 'nameptr :=
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
#if NAME_FULL
    { s nameptr "{ff~}{vv~}{ll}{, jj}" format.name$ 't :=
#else
    { s nameptr "{f.~}{vv~}{ll}{, jj}" format.name$ 't :=
#endif NAME_FULL
      nameptr #1 >
        { namesleft #1 >
            { ", " * t * }
            { numnames #2 >
                { "," * }
                'skip$
              if$
              t "others" =
                { " et~al." * }
                { " and " * t * }
              if$
            }
          if$
        }
        't
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

FUNCTION {format.authors}
{ author empty$
    { "" }
    { author format.names }
  if$
}

FUNCTION {format.editors}
{ editor empty$
    { "" }
    { editor format.names
      editor num.names$ #1 >
        { ", editors" * }
        { ", editor" * }
      if$
    }
  if$
}

FUNCTION {format.isbn}
{ isbn empty$
    { "" }
    { new.block "ISBN " isbn * }
  if$
}

FUNCTION {format.issn}
{ issn empty$
    { "" }
    { new.block "ISSN " issn * }
  if$
}

% The format.title function is used for non-book-like titles.
% For most styles we convert to lowercase (except for the very first letter,
% and except for the first one after a colon (followed by whitespace)),
% and hope the user has brace-surrounded words that need to stay capitilized;
% for some styles, however, we leave it as it is in the database.

FUNCTION {format.title}
{ title empty$
    { "" }
#if ATIT_LOWER
    { title "t" change.case$ }
#else
    'title
#endif ATIT_LOWER
  if$
}

% By default, BibTeX sets the global integer variable global.max$ to the BibTeX
% constant glob_str_size, the maximum length of a global string variable.
% Analogously, BibTeX sets the global integer variable entry.max$ to
% ent_str_size, the maximum length of an entry string variable.
% The style designer may change these if necessary (but this is unlikely)

% The n.dashify function makes each single `-' in a string a double `--'
% if it's not already
%
% pseudoVAR: pageresult: STRING         (it's what's accumulated on the stack)
%
% n.dashify(s) ==
%  BEGIN
%       t := s
%       pageresult := ""
%       while (not empty$(t))
%         do
%           if (first character of t = "-")
%             then
%               if (next character isn't)
%                 then
%                   pageresult := pageresult * "--"
%                   t := t with the "-" removed
%                 else
%                   while (first character of t = "-")
%                     do
%                       pageresult := pageresult * "-"
%                       t := t with the "-" removed
%                     od
%               fi
%             else
%               pageresult := pageresult * the first character
%               t := t with the first character removed
%           fi
%         od
%       return pageresult
%  END

FUNCTION {n.dashify}
{ 't :=
  ""
    { t empty$ not }
    { t #1 #1 substring$ "-" =
        { t #1 #2 substring$ "--" = not
            { "--" *
              t #2 global.max$ substring$ 't :=
            }
            {   { t #1 #1 substring$ "-" = }
                { "-" *
                  t #2 global.max$ substring$ 't :=
                }
              while$
            }
          if$
        }
        { t #1 #1 substring$ *
          t #2 global.max$ substring$ 't :=
        }
      if$
    }
  while$
}

% The format.date function is for the month and year, but we give a warning if
% there's an empty year but the month is there, and we return the empty string
% if they're both empty.

FUNCTION {format.date}
{ year empty$
    { month empty$
        { "" }
        { "there's a month but no year in " cite$ * warning$
          month
        }
      if$
    }
    { month empty$
        'year
        { month " " * year * }
      if$
    }
  if$
}

% The format.btitle is for formatting the title field when it is a book-like
% entry---the style used here keeps it in uppers-and-lowers and emphasizes it.

FUNCTION {format.btitle}
{ title emphasize
}

% For several functions we'll need to connect two strings with a
% tie (~) if the second one isn't very long (fewer than 3 characters).
% The tie.or.space.connect function does that.  It concatenates the two
% strings on top of the stack, along with either a tie or space between
% them, and puts this concatenation back onto the stack:
%
% tie.or.space.connect(str1,str2) ==
%    BEGIN
%       if text.length$(str2) < 3
%         then return the concatenation of str1, "~", and str2
%         else return the concatenation of str1, " ", and str2
%    END

FUNCTION {tie.or.space.connect}
{ duplicate$ text.length$ #3 <
    { "~" }
    { " " }
  if$
  swap$ * *
}

% The either.or.check function complains if both fields or an either-or pair
% are nonempty.
%
% either.or.check(t,s) ==
%  BEGIN
%       if empty$(s) then
%           warning$(can't use both " * t * " fields in " * cite$)
%       fi
%  END

FUNCTION {either.or.check}
{ empty$
    'pop$
    { "can't use both " swap$ * " fields in " * cite$ * warning$ }
  if$
}

% The format.bvolume function is for formatting the volume and perhaps
% series name of a multivolume work.  If both a volume and a series field
% are there, we assume the series field is the title of the whole multivolume
% work (the title field should be the title of the thing being referred to),
% and we add an "of <series>".  This function is called in mid-sentence.

FUNCTION {format.bvolume}
{ volume empty$
    { "" }
    { "volume" volume tie.or.space.connect
      series empty$
        'skip$
        { " of " * series emphasize * }
      if$
      "volume and number" number either.or.check
    }
  if$
}

% The format.number.series function is for formatting the series name
% and perhaps number of a work in a series.  This function is similar to
% format.bvolume, although for this one the series must exist (and the
% volume must not exist).  If the number field is empty we output either
% the series field unchanged if it exists or else the null string.
% If both the number and series fields are there we assume the series field
% gives the name of the whole series (the title field should be the title
% of the work being one referred to), and we add an "in <series>".
% We capitilize Number when this function is used at the beginning of a block.

FUNCTION {format.number.series}
{ volume empty$
    { number empty$
        { series field.or.null }
        { output.state mid.sentence =
            { "number" }
            { "Number" }
          if$
          number tie.or.space.connect
          series empty$
            { "there's a number but no series in " cite$ * warning$ }
            { " in " * series * }
          if$
        }
      if$
    }
    { "" }
  if$
}

% The format.edition function appends " edition" to the edition, if present.
% We lowercase the edition (it should be something like "Third"), because
% this doesn't start a sentence.

FUNCTION {format.edition}
{ edition empty$
    { "" }
    { output.state mid.sentence =
        { edition "l" change.case$ " edition" * }
        { edition "t" change.case$ " edition" * }
      if$
    }
  if$
}

% The format.pages function is used for formatting a page range in a book
% (and in rare circumstances, an article).
%
% The multi.page.check function examines the page field for a "-" or "," or "+"
% so that format.pages can use "page" instead of "pages" if none exists.
% Note: global.max$ here means "take the rest of the string"
%
% VAR: multiresult: INTEGER     (actually, a boolean)
%
% multi.page.check(s) ==
%  BEGIN
%       t := s
%       multiresult := false
%       while ((not multiresult) and (not empty$(t)))
%         do
%           if (first character of t = "-" or "," or "+")
%             then multiresult := true
%             else t := t with the first character removed
%           fi
%         od
%       return multiresult
%  END

INTEGERS { multiresult }

FUNCTION {multi.page.check}
{ 't :=
  #0 'multiresult :=
    { multiresult not
      t empty$ not
      and
    }
    { t #1 #1 substring$
      duplicate$ "-" =
      swap$ duplicate$ "," =
      swap$ "+" =
      or or
        { #1 'multiresult := }
        { t #2 global.max$ substring$ 't := }
      if$
    }
  while$
  multiresult
}

% This function doesn't begin a sentence so "pages" isn't capitalized.
% Other functions that use this should keep that in mind.

FUNCTION {format.pages}
{ pages empty$
    { "" }
    { pages multi.page.check
        { "pages" pages n.dashify tie.or.space.connect }
        { "page" pages tie.or.space.connect }
      if$
    }
  if$
}

% The format.vol.num.pages function is for the volume, number, and page range
% of a journal article.  We use the format:  vol(number):pages, with some
% variations for empty fields.  This doesn't begin a sentence.

FUNCTION {format.vol.num.pages}
{ volume field.or.null
  number empty$
    'skip$
    { "\penalty0 (" number * ")" * *
      volume empty$
        { "there's a number but no volume in " cite$ * warning$ }
        'skip$
      if$
    }
  if$
  pages empty$
    'skip$
    { duplicate$ empty$
        { pop$ format.pages }
        { ":\penalty0 " * pages n.dashify * }
      if$
    }
  if$
}


% The format.chapter.pages, if the chapter is present, puts whatever is in the
% type field (or else "chapter" if type is empty) in front of a chapter number.
% It then appends the pages, if present.  This doesn't begin a sentence.

FUNCTION {format.chapter.pages}
{ chapter empty$
    'format.pages
    { type empty$
        { "chapter" }
        { type "l" change.case$ }
      if$
      chapter tie.or.space.connect
      pages empty$
        'skip$
        { ", " * format.pages * }
      if$
    }
  if$
}

% The format.in.ed.booktitle function is used for starting out a sentence
% that begins "In <booktitle>", putting an editor before the title if one
% exists.

FUNCTION {format.in.ed.booktitle}
{ booktitle empty$
    { "" }
    { editor empty$
        { "In " booktitle emphasize * }
        { "In " format.editors * ", " * booktitle emphasize * }
      if$
    }
  if$
}

% The function empty.misc.check complains if all six fields are empty, and
% if there's been no sorting or alphabetic-label complaint.

FUNCTION {empty.misc.check}
{ author empty$ title empty$ howpublished empty$
  month empty$ year empty$ note empty$
  and and and and and
#if SORTED
  key empty$ not and
#else !SORTED
#if LAB_ALPH
  key empty$ not and
#endif LAB_ALPH
#endif SORTED
    { "all relevant fields are empty in " cite$ * warning$ }
    'skip$
  if$
}

% The function format.thesis.type returns either the (case-changed) type field,
% if it is defined, or else the default string already on the stack
% (like "Master's thesis" or "PhD thesis").

FUNCTION {format.thesis.type}
{ type empty$
    'skip$
    { pop$
      type "t" change.case$
    }
  if$
}

% The function format.tr.number makes a string starting with "Technical Report"
% (or type, if that field is defined), followed by the number if there is one;
% it returns the starting part (with a case change) even if there is no number.
% This is used at the beginning of a sentence.

FUNCTION {format.tr.number}
{ type empty$
    { "Technical Report" }
    'type
  if$
  number empty$
    { "t" change.case$ }
    { number tie.or.space.connect }
  if$
}

% Now come the cross-referencing functions (these are invoked because
% one entry in the database file(s) cross-references another, by giving
% the other entry's database key in a `crossref' field).  This feature
% allows one or more titled things that are part of a larger titled
% thing to cross-reference the larger thing.  These styles allow for
% five posibilities: (1) an ARTICLE may cross-reference an ARTICLE;
% (2) a BOOK, (3) INBOOK, or (4) INCOLLECTION may cross-reference a BOOK;
% or (5) an INPROCEEDINGS may cross-reference a PROCEEDINGS.
% Each of these is explained in more detail later.
%
% An ARTICLE entry type may cross reference another ARTICLE (this is
% intended for when an entire journal is devoted to a single topic---
% but since there is no JOURNAL entry type, the journal, too, should be
% classified as an ARTICLE but without the author and title fields).
% This will result in two warning messages for the journal's entry
% if it's included in the reference list, but such is life.
%
% format.article.crossref ==
%  BEGIN
%       if empty$(key) then
%           if empty$(journal) then
%               warning$("need key or journal for " * cite$ *
%                                               " to crossref " * crossref)
%               return(" \cite{" * crossref * "}")
%           else
%               return("In " * emphasize.correct (journal) *
%                                               " \cite{" * crossref * "}")
%               fi
%       else
%           return("In " * key * " \cite{" * crossref * "}")
%       fi
%  END
%
% The other cross-referencing functions are similar, so no "comment version"
% will be given for them.

FUNCTION {format.article.crossref}
{ key empty$
    { journal empty$
        { "need key or journal for " cite$ * " to crossref " * crossref *
          warning$
          ""
        }
        { "In {\em " journal * "\/}" * }
      if$
    }
    { "In " key * }
  if$
  " \cite{" * crossref * "}" *
}

% We use just the last names of editors for a cross reference: either
% "editor", or "editor1 and editor2", or "editor1 et~al." depending on
% whether there are one, or two, or more than two editors.

FUNCTION {format.crossref.editor}
{ editor #1 "{vv~}{ll}" format.name$
  editor num.names$ duplicate$
  #2 >
    { pop$ " et~al." * }
    { #2 <
        'skip$
        { editor #2 "{ff }{vv }{ll}{ jj}" format.name$ "others" =
            { " et~al." * }
            { " and " * editor #2 "{vv~}{ll}" format.name$ * }
          if$
        }
      if$
    }
  if$
}

% A BOOK (or INBOOK) entry type (assumed to be for a single volume in a
% multivolume work) may cross reference another BOOK (the entire multivolume).
% Usually there will be an editor, in which case we use that to construct the
% cross reference; otherwise we use a nonempty key field or else the series
% field (since the series gives the title of the multivolume work).

FUNCTION {format.book.crossref}
{ volume empty$
    { "empty volume in " cite$ * "'s crossref of " * crossref * warning$
      "In "
    }
    { "Volume" volume tie.or.space.connect
      " of " *
    }
  if$
  editor empty$
  editor field.or.null author field.or.null =
  or
    { key empty$
        { series empty$
            { "need editor, key, or series for " cite$ * " to crossref " *
              crossref * warning$
              "" *
            }
            { "{\em " * series * "\/}" * }
          if$
        }
        { key * }
      if$
    }
    { format.crossref.editor * }
  if$
  " \cite{" * crossref * "}" *
}

% An INCOLLECTION entry type may cross reference a BOOK (assumed to be the
% collection), or an INPROCEEDINGS may cross reference a PROCEEDINGS.
% Often there will be an editor, in which case we use that to construct
% the cross reference; otherwise we use a nonempty key field or else
% the booktitle field (which gives the cross-referenced work's title).

FUNCTION {format.incoll.inproc.crossref}
{ editor empty$
  editor field.or.null author field.or.null =
  or
    { key empty$
        { booktitle empty$
            { "need editor, key, or booktitle for " cite$ * " to crossref " *
              crossref * warning$
              ""
            }
            { "In {\em " booktitle * "\/}" * }
          if$
        }
        { "In " key * }
      if$
    }
    { "In " format.crossref.editor * }
  if$
  " \cite{" * crossref * "}" *
}

% Now we define the type functions for all entry types that may appear
% in the .BIB file---e.g., functions like `article' and `book'.  These
% are the routines that actually generate the .BBL-file output for
% the entry.  These must all precede the READ command.  In addition, the
% style designer should have a function `default.type' for unknown types.
% Note: The fields (within each list) are listed in order of appearance,
% except as described for an `inbook' or a `proceedings'.
%
% The article function is for an article in a journal.  An article may
% CROSSREF another article.
%       Required fields: author, title, journal, year
%       Optional fields: volume, number, pages, month, note
%
% article ==
%  BEGIN
%       output.bibitem
%       output.check(format.authors,"author")
%       new.block
%       output.check(format.title,"title")
%       new.block
%       if missing$(crossref) then
%           output.check(emphasize(journal),"journal")
%           output(format.vol.num.pages)
%           output.check(format.date,"year")
%       else
%           output.nonnull(format.article.crossref)
%           output(format.pages)
%       fi
%       new.block
%       output(note)
%       fin.entry
%  END
%
% The book function is for a whole book.  A book may CROSSREF another book.
%       Required fields: author or editor, title, publisher, year
%       Optional fields: volume or number, series, address, edition, month,
%                       note
%
% book ==
%  BEGIN
%       if empty$(author) then output.check(format.editors,"author and editor")
%       else    output.check(format.authors,"author")
%               if missing$(crossref) then
%                   either.or.check("author and editor",editor)
%               fi
%       fi
%       new.block
%       output.check(format.btitle,"title")
%       if missing$(crossref) then
%           output(format.bvolume)
%           new.block
%           output(format.number.series)
%           new.sentence
%           output.check(publisher,"publisher")
%           output(address)
%       else
%           new.block
%           output.nonnull(format.book.crossref)
%       fi
%       output(format.edition)
%       output.check(format.date,"year")
%       new.block
%       output(note)
%       fin.entry
%  END
%
% The other entry functions are all quite similar, so no "comment version"
% will be given for them.

FUNCTION {article}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  crossref missing$
    { journal emphasize "journal" output.check
      format.vol.num.pages output
      format.date "year" output.check
    }
    { format.article.crossref output.nonnull
      format.pages output
    }
  if$
  new.block
  note output
  fin.entry
}

FUNCTION {book}
{ output.bibitem
  author empty$
    { format.editors "author and editor" output.check }
    { format.authors output.nonnull
      crossref missing$
        { "author and editor" editor either.or.check }
        'skip$
      if$
    }
  if$
  new.block
  format.btitle "title" output.check
  crossref missing$
    { format.bvolume output
      new.block
      format.number.series output
      new.sentence
      publisher "publisher" output.check
      address output
    }
    { new.block
      format.book.crossref output.nonnull
    }
  if$
  format.edition output
  format.date "year" output.check
  format.isbn output
  new.block
  note output
  fin.entry
}

% A booklet is a bound thing without a publisher or sponsoring institution.
%       Required: title
%       Optional: author, howpublished, address, month, year, note

FUNCTION {booklet}
{ output.bibitem
  format.authors output
  new.block
  format.title "title" output.check
  howpublished address new.block.checkb
  howpublished output
  address output
  format.date output
  format.isbn output
  new.block
  note output
  fin.entry
}

% For the conference entry type, see inproceedings.

% An inbook is a piece of a book: either a chapter and/or a page range.
% It may CROSSREF a book.  If there's no volume field, the type field
% will come before number and series.
%       Required: author or editor, title, chapter and/or pages, publisher,year
%       Optional: volume or number, series, type, address, edition, month, note

FUNCTION {inbook}
{ output.bibitem
  author empty$
    { format.editors "author and editor" output.check }
    { format.authors output.nonnull
      crossref missing$
        { "author and editor" editor either.or.check }
        'skip$
      if$
    }
  if$
  new.block
  format.btitle "title" output.check
  crossref missing$
    { format.bvolume output
      format.chapter.pages "chapter and pages" output.check
      new.block
      format.number.series output
      new.sentence
      publisher "publisher" output.check
      address output
    }
    { format.chapter.pages "chapter and pages" output.check
      new.block
      format.book.crossref output.nonnull
    }
  if$
  format.edition output
  format.date "year" output.check
  format.isbn output
  new.block
  note output
  fin.entry
}

% An incollection is like inbook, but where there is a separate title
% for the referenced thing (and perhaps an editor for the whole).
% An incollection may CROSSREF a book.
%       Required: author, title, booktitle, publisher, year
%       Optional: editor, volume or number, series, type, chapter, pages,
%                       address, edition, month, note

FUNCTION {incollection}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  crossref missing$
    { format.in.ed.booktitle "booktitle" output.check
      format.bvolume output
      format.number.series output
      format.chapter.pages output
      new.sentence
      publisher "publisher" output.check
      address output
      format.edition output
      format.date "year" output.check
    }
    { format.incoll.inproc.crossref output.nonnull
      format.chapter.pages output
    }
  if$
  format.isbn output
  new.block
  note output
  fin.entry
}

% An inproceedings is an article in a conference proceedings, and it may
% CROSSREF a proceedings.  If there's no address field, the month (& year)
% will appear just before note.
%       Required: author, title, booktitle, year
%       Optional: editor, volume or number, series, pages, address, month,
%                       organization, publisher, note

FUNCTION {inproceedings}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  crossref missing$
    { format.in.ed.booktitle "booktitle" output.check
      format.bvolume output
      format.number.series output
      format.pages output
      address empty$
        { organization publisher new.sentence.checkb
          organization output
          publisher output
          format.date "year" output.check
        }
        { address output.nonnull
          format.date "year" output.check
          new.sentence
          organization output
          publisher output
        }
      if$
    }
    { format.incoll.inproc.crossref output.nonnull
      format.pages output
    }
  if$
  format.isbn output
  new.block
  note output
  fin.entry
}

% The conference function is included for Scribe compatibility.

FUNCTION {conference} { inproceedings }

% A manual is technical documentation.
%       Required: title
%       Optional: author, organization, address, edition, month, year, note

FUNCTION {manual}
{ output.bibitem
  author empty$
    { organization empty$
        'skip$
        { organization output.nonnull
          address output
        }
      if$
    }
    { format.authors output.nonnull }
  if$
  new.block
  format.btitle "title" output.check
  author empty$
    { organization empty$
        { address new.block.checka
          address output
        }
        'skip$
      if$
    }
    { organization address new.block.checkb
      organization output
      address output
    }
  if$
  format.edition output
  format.date output
  new.block
  note output
  fin.entry
}

% A mastersthesis is a Master's thesis.
%       Required: author, title, school, year
%       Optional: type, address, month, note

FUNCTION {mastersthesis}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  "Master's thesis" format.thesis.type output.nonnull
  school "school" output.check
  address output
  format.date "year" output.check
  new.block
  note output
  fin.entry
}

% A misc is something that doesn't fit elsewhere.
%       Required: at least one of the `optional' fields
%       Optional: author, title, howpublished, month, year, note

FUNCTION {misc}
{ output.bibitem
  format.authors output
  title howpublished new.block.checkb
  format.title output
  howpublished new.block.checka
  howpublished output
  format.date output
  format.issn output
  new.block
  note output
  fin.entry
  empty.misc.check
}

% A phdthesis is like a mastersthesis.
%       Required: author, title, school, year
%       Optional: type, address, month, note

FUNCTION {phdthesis}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.btitle "title" output.check
  new.block
  "PhD thesis" format.thesis.type output.nonnull
  school "school" output.check
  address output
  format.date "year" output.check
  new.block
  note output
  fin.entry
}

% A periodical is a publication that appears at regular
% intervals.  This includes journals, magazines, and newspapers.
% If there is an organization but no editor field, the
% organization will appear as the first optional field (we try to
% make the first block nonempty); if there's no address field,
% the month (& year) will appear just before note.
%       Required: title, key
%       Optional: editor, volume, number, series, address, month, year,
%                       organization, publisher, note, issn,
%                       howpublished

FUNCTION {periodical}
{ output.bibitem
  editor empty$
    { organization output }
    { format.editors output.nonnull }
  if$
  new.block
  title emphasize "title" output.check
%  format.bvolume output
%  format.number.series output
  format.vol.num.pages output
  format.date output
  format.issn output
  new.sentence
  publisher output
  address output
  howpublished new.block.checka
  howpublished output
  new.block
  note output
  fin.entry
}

% A proceedings is a conference proceedings.
% If there is an organization but no editor field, the organization will
% appear as the first optional field (we try to make the first block nonempty);
% if there's no address field, the month (& year) will appear just before note.
%       Required: title, year
%       Optional: editor, volume or number, series, address, month,
%                       organization, publisher, note

FUNCTION {proceedings}
{ output.bibitem
  editor empty$
    { organization output }
    { format.editors output.nonnull }
  if$
  new.block
  format.btitle "title" output.check
  format.bvolume output
  format.number.series output
  address empty$
    { editor empty$
        { publisher new.sentence.checka }
        { organization publisher new.sentence.checkb
          organization output
        }
      if$
      publisher output
      format.date "year" output.check
    }
    { address output.nonnull
      format.date "year" output.check
      new.sentence
      editor empty$
        'skip$
        { organization output }
      if$
      publisher output
    }
  if$
  format.isbn output
  new.block
  note output
  fin.entry
}

% A techreport is a technical report.
%       Required: author, title, institution, year
%       Optional: type, number, address, month, note

FUNCTION {techreport}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  format.tr.number output.nonnull
  institution "institution" output.check
  address output
  format.date "year" output.check
  new.block
  note output
  fin.entry
}

% An unpublished is something that hasn't been published.
%       Required: author, title, note
%       Optional: month, year

FUNCTION {unpublished}
{ output.bibitem
  format.authors "author" output.check
  new.block
  format.title "title" output.check
  new.block
  note "note" output.check
  format.date output
  fin.entry
}

% We use entry type `misc' for an unknown type; BibTeX gives a warning.

FUNCTION {default.type} { misc }

% Here are macros for common things that may vary from style to style.
% Users are encouraged to use these macros.
%
% Months are either written out in full or abbreviated

#if MONTH_FULL

MACRO {jan} {"January"}

MACRO {feb} {"February"}

MACRO {mar} {"March"}

MACRO {apr} {"April"}

MACRO {may} {"May"}

MACRO {jun} {"June"}

MACRO {jul} {"July"}

MACRO {aug} {"August"}

MACRO {sep} {"September"}

MACRO {oct} {"October"}

MACRO {nov} {"November"}

MACRO {dec} {"December"}

#else !MONTH_FULL

MACRO {jan} {"Jan."}

MACRO {feb} {"Feb."}

MACRO {mar} {"Mar."}

MACRO {apr} {"Apr."}

MACRO {may} {"May"}

MACRO {jun} {"June"}

MACRO {jul} {"July"}

MACRO {aug} {"Aug."}

MACRO {sep} {"Sept."}

MACRO {oct} {"Oct."}

MACRO {nov} {"Nov."}

MACRO {dec} {"Dec."}

#endif MONTH_FULL

% Journals are either written out in full or abbreviated;
% the abbreviations are like those found in ACM publications.
%
% To get a completely different set of abbreviations, it may be best to make
% a separate .bib file with nothing but those abbreviations; users could then
% include that file name as the first argument to the \bibliography command

#if JOUR_FULL

MACRO {acmcs} {"ACM Computing Surveys"}

MACRO {acta} {"Acta Informatica"}

MACRO {cacm} {"Communications of the ACM"}

MACRO {ibmjrd} {"IBM Journal of Research and Development"}

MACRO {ibmsj} {"IBM Systems Journal"}

MACRO {ieeese} {"IEEE Transactions on Software Engineering"}

MACRO {ieeetc} {"IEEE Transactions on Computers"}

MACRO {ieeetcad}
 {"IEEE Transactions on Computer-Aided Design of Integrated Circuits"}

MACRO {ipl} {"Information Processing Letters"}

MACRO {jacm} {"Journal of the ACM"}

MACRO {jcss} {"Journal of Computer and System Sciences"}

MACRO {scp} {"Science of Computer Programming"}

MACRO {sicomp} {"SIAM Journal on Computing"}

MACRO {tocs} {"ACM Transactions on Computer Systems"}

MACRO {tods} {"ACM Transactions on Database Systems"}

MACRO {tog} {"ACM Transactions on Graphics"}

MACRO {toms} {"ACM Transactions on Mathematical Software"}

MACRO {toois} {"ACM Transactions on Office Information Systems"}

MACRO {toplas} {"ACM Transactions on Programming Languages and Systems"}

MACRO {tcs} {"Theoretical Computer Science"}

#else !JOUR_FULL

MACRO {acmcs} {"ACM Comput. Surv."}

MACRO {acta} {"Acta Inf."}

MACRO {cacm} {"Commun. ACM"}

MACRO {ibmjrd} {"IBM J. Res. Dev."}

MACRO {ibmsj} {"IBM Syst.~J."}

MACRO {ieeese} {"IEEE Trans. Softw. Eng."}

MACRO {ieeetc} {"IEEE Trans. Comput."}

MACRO {ieeetcad}
 {"IEEE Trans. Comput.-Aided Design Integrated Circuits"}

MACRO {ipl} {"Inf. Process. Lett."}

MACRO {jacm} {"J.~ACM"}

MACRO {jcss} {"J.~Comput. Syst. Sci."}

MACRO {scp} {"Sci. Comput. Programming"}

MACRO {sicomp} {"SIAM J. Comput."}

MACRO {tocs} {"ACM Trans. Comput. Syst."}

MACRO {tods} {"ACM Trans. Database Syst."}

MACRO {tog} {"ACM Trans. Gr."}

MACRO {toms} {"ACM Trans. Math. Softw."}

MACRO {toois} {"ACM Trans. Office Inf. Syst."}

MACRO {toplas} {"ACM Trans. Prog. Lang. Syst."}

MACRO {tcs} {"Theoretical Comput. Sci."}

#endif JOUR_FULL

% Now we read in the .BIB entries.

READ

% The sortify function converts to lower case after purify$ing; it's
% used in sorting and in computing alphabetic labels after sorting
%
% The chop.word(w,len,s) function returns either s or, if the first len
% letters of s equals w (this comparison is done in the third line of the
% function's definition), it returns that part of s after w.

#if SORTED

FUNCTION {sortify}
{ purify$
  "l" change.case$
}

INTEGERS { len }

FUNCTION {chop.word}
{ 's :=
  'len :=
  s #1 len substring$ =
    { s len #1 + global.max$ substring$ }
    's
  if$
}

#else !SORTED
#if LAB_ALPH

% We need the chop.word stuff for the dubious unsorted-list-with-labels case.

INTEGERS { len }

FUNCTION {chop.word}
{ 's :=
  'len :=
  s #1 len substring$ =
    { s len #1 + global.max$ substring$ }
    's
  if$
}

#endif LAB_ALPH
#endif SORTED

% This long comment applies only to alphabetic labels
%
% The format.lab.names function makes a short label by using the initials of
% the von and Last parts of the names (but if there are more than four names,
% (i.e., people) it truncates after three and adds a superscripted "+";
% it also adds such a "+" if the last of multiple authors is "others").
% If there is only one name, and its von and Last parts combined have just
% a single name-token ("Knuth" has a single token, "Brinch Hansen" has two),
% we take the first three letters of the last name.  The boolean
% et.al.char.used tells whether we've used a superscripted "+", so that we
% know whether to include a LaTeX macro for it.
%
% format.lab.names(s) ==
%  BEGIN
%       numnames := num.names$(s)
%       if numnames > 1 then
%           if numnames > 4 then
%               namesleft := 3
%           else
%               namesleft := numnames
%           nameptr := 1
%           nameresult := ""
%           while namesleft > 0
%             do
%               if (name_ptr = numnames) and
%                    format.name$(s, nameptr, "{ff }{vv }{ll}{ jj}") = "others"
%                  then nameresult := nameresult * "{\etalchar{+}}"
%                       et.al.char.used := true
%                  else nameresult := nameresult *
%                               format.name$(s, nameptr, "{v{}}{l{}}")
%               nameptr := nameptr + 1
%               namesleft := namesleft - 1
%             od
%           if numnames > 4 then
%               nameresult := nameresult * "{\etalchar{+}}"
%               et.al.char.used := true
%       else
%           t := format.name$(s, 1, "{v{}}{l{}}")
%           if text.length$(t) < 2 then % there's just one name-token
%               nameresult := text.prefix$(format.name$(s,1,"{ll}"),3)
%           else
%               nameresult := t
%           fi
%       fi
%       return nameresult
%  END
%
% Exactly what fields we look at in constructing the primary part of the label
% depends on the entry type; this selectivity (as opposed to, say, always
% looking at author, then editor, then key) helps ensure that "ignored" fields,
% as described in the LaTeX book, really are ignored.  Note that MISC is part
% of the deepest `else' clause in the nested part of calc.label; thus, any
% unrecognized entry type in the database is handled correctly.
%
% There is one auxiliary function for each of the four different sequences of
% fields we use.  The first of these functions looks at the author field, and
% then, if necessary, the key field.  The other three functions, which might
% look at two fields and the key field, are similar, except that the key field
% takes precedence over the organization field (for labels---not for sorting).
%
% The calc.label function calculates the preliminary label of an entry, which
% is formed by taking three letters of information from the author or editor or
% key or organization field (depending on the entry type and on what's empty,
% but ignoring a leading "The " in the organization), and appending the last
% two characters (digits) of the year. It is an error if the appropriate fields
% among author, editor, organization, and key are missing, and we use
% the first three letters of the cite$ in desperation when this happens.
% The resulting label has the year part, but not the name part, purify$ed
% (purify$ing the year allows some sorting shenanigans by the user).
%
% This function also calculates the version of the label to be used in sorting.
%
% The final label may need a trailing 'a', 'b', etc., to distinguish it from
% otherwise identical labels, but we can't calculated those "extra.label"s
% until after sorting.
%
% calc.label ==
%  BEGIN
%       if type$ = "book" or "inbook" then
%           author.editor.key.label
%       else if type$ = "proceedings" then
%           editor.key.organization.label
%       else if type$ = "manual" then
%           author.key.organization.label
%       else
%           author.key.label
%       fi fi fi
%       label := label * substring$(purify$(field.or.null(year)), -1, 2)
%               % assuming we will also sort, we calculate a sort.label
%       sort.label := sortify(label), but use the last four, not two, digits
%  END

#if LAB_ALPH

INTEGERS { et.al.char.used }

FUNCTION {initialize.et.al.char.used}
{ #0 'et.al.char.used :=
}

EXECUTE {initialize.et.al.char.used}

FUNCTION {format.lab.names}
{ 's :=
  s num.names$ 'numnames :=
  numnames #1 >
    { numnames #4 >
        { #3 'namesleft := }
        { numnames 'namesleft := }
      if$
      #1 'nameptr :=
      ""
        { namesleft #0 > }
        { nameptr numnames =
            { s nameptr "{ff }{vv }{ll}{ jj}" format.name$ "others" =
                { "{\etalchar{+}}" *
                  #1 'et.al.char.used :=
                }
                { s nameptr "{v{}}{l{}}" format.name$ * }
              if$
            }
            { s nameptr "{v{}}{l{}}" format.name$ * }
          if$
          nameptr #1 + 'nameptr :=
          namesleft #1 - 'namesleft :=
        }
      while$
      numnames #4 >
        { "{\etalchar{+}}" *
          #1 'et.al.char.used :=
        }
        'skip$
      if$
    }
    { s #1 "{v{}}{l{}}" format.name$
      duplicate$ text.length$ #2 <
        { pop$ s #1 "{ll}" format.name$ #3 text.prefix$ }
        'skip$
      if$
    }
  if$
}

FUNCTION {author.key.label}
{ author empty$
    { key empty$
#if SORTED
        { cite$ #1 #3 substring$ }
#else !SORTED           % need warning here because we won't give it later
        { "for label, need author or key in " cite$ * warning$
          cite$ #1 #3 substring$
        }
#endif SORTED
        { key #3 text.prefix$ }
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {author.editor.key.label}
{ author empty$
    { editor empty$
        { key empty$
#if SORTED
            { cite$ #1 #3 substring$ }
#else !SORTED           % need warning here because we won't give it later
            { "for label, need author, editor, or key in " cite$ * warning$
              cite$ #1 #3 substring$
            }
#endif SORTED
            { key #3 text.prefix$ }
          if$
        }
        { editor format.lab.names }
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {author.key.organization.label}
{ author empty$
    { key empty$
        { organization empty$
#if SORTED
            { cite$ #1 #3 substring$ }
#else !SORTED           % need warning here because we won't give it later
            { "for label, need author, key, or organization in " cite$ *
                                                                warning$
              cite$ #1 #3 substring$
            }
#endif SORTED
            { "The " #4 organization chop.word #3 text.prefix$ }
          if$
        }
        { key #3 text.prefix$ }
      if$
    }
    { author format.lab.names }
  if$
}

FUNCTION {editor.key.organization.label}
{ editor empty$
    { key empty$
        { organization empty$
#if SORTED
            { cite$ #1 #3 substring$ }
#else !SORTED           % need warning here because we won't give it later
            { "for label, need editor, key, or organization in " cite$ *
                                                                warning$
              cite$ #1 #3 substring$
            }
#endif SORTED
            { "The " #4 organization chop.word #3 text.prefix$ }
          if$
        }
        { key #3 text.prefix$ }
      if$
    }
    { editor format.lab.names }
  if$
}

FUNCTION {calc.label}
{ type$ "book" =
  type$ "inbook" =
  or
    'author.editor.key.label
    { type$ "proceedings" =
        'editor.key.organization.label
        { type$ "manual" =
            'author.key.organization.label
            'author.key.label
          if$
        }
      if$
    }
  if$
  duplicate$
  year field.or.null purify$ #-1 #2 substring$
  *
  'label :=
  year field.or.null purify$ #-1 #4 substring$
  *
  sortify 'sort.label :=
}

% It doesn't seem like a particularly good idea to use an order-of-citation
% reference list when using alphabetic labels, but we need to have a
% special pass to calculate labels when this happens.

#if !SORTED

ITERATE {calc.label}

#endif !SORTED

#endif LAB_ALPH

% When sorting, we compute the sortkey by executing "presort" on each entry.
% The presort key contains a number of "sortify"ed strings, concatenated
% with multiple blanks between them.  This makes things like "brinch  per"
% come before "brinch hansen  per".
%
% The fields used here are: the sort.label for alphabetic labels (as set by
% calc.label), followed by the author names (or editor names or organization
% (with a leading "The " removed) or key field, depending on entry type and on
% what's empty), followed by year, followed by the first bit of the title
% (chopping off a leading "The ", "A ", or "An ").
% Names are formatted: Von Last First Junior.
% The names within a part will be separated by a single blank
% (such as "brinch hansen"), two will separate the name parts themselves
% (except the von and last), three will separate the names,
% four will separate the names from year (and from label, if alphabetic),
% and four will separate year from title.
%
% The sort.format.names function takes an argument that should be in
% BibTeX name format, and returns a string containing "   "-separated
% names in the format described above.  The function is almost the same
% as format.names.

#if SORTED

FUNCTION {sort.format.names}
{ 's :=
  #1 'nameptr :=
  ""
  s num.names$ 'numnames :=
  numnames 'namesleft :=
    { namesleft #0 > }
    { nameptr #1 >
        { "   " * }
        'skip$
      if$
#if NAME_FULL
      s nameptr "{vv{ } }{ll{ }}{  ff{ }}{  jj{ }}" format.name$ 't :=
#else
      s nameptr "{vv{ } }{ll{ }}{  f{ }}{  jj{ }}" format.name$ 't :=
#endif NAME_FULL
      nameptr numnames = t "others" = and
        { "et al" * }
        { t sortify * }
      if$
      nameptr #1 + 'nameptr :=
      namesleft #1 - 'namesleft :=
    }
  while$
}

% The sort.format.title function returns the argument,
% but first any leading "A "'s, "An "'s, or "The "'s are removed.
% The chop.word function uses s, so we need another string variable, t

FUNCTION {sort.format.title}
{ 't :=
  "A " #2
    "An " #3
      "The " #4 t chop.word
    chop.word
  chop.word
  sortify
  #1 global.max$ substring$
}

% The auxiliary functions here, for the presort function, are analogous to
% the ones for calc.label; the same comments apply, except that the
% organization field takes precedence here over the key field.  For sorting
% purposes, we still remove a leading "The " from the organization field.

FUNCTION {author.sort}
{ author empty$
    { key empty$
        { "to sort, need author or key in " cite$ * warning$
          ""
        }
        { key sortify }
      if$
    }
    { author sort.format.names }
  if$
}

FUNCTION {author.editor.sort}
{ author empty$
    { editor empty$
        { key empty$
            { "to sort, need author, editor, or key in " cite$ * warning$
              ""
            }
            { key sortify }
          if$
        }
        { editor sort.format.names }
      if$
    }
    { author sort.format.names }
  if$
}

FUNCTION {author.organization.sort}
{ author empty$
    { organization empty$
        { key empty$
            { "to sort, need author, organization, or key in " cite$ * warning$
              ""
            }
            { key sortify }
          if$
        }
        { "The " #4 organization chop.word sortify }
      if$
    }
    { author sort.format.names }
  if$
}

FUNCTION {editor.organization.sort}
{ editor empty$
    { organization empty$
        { key empty$
            { "to sort, need editor, organization, or key in " cite$ * warning$
              ""
            }
            { key sortify }
          if$
        }
        { "The " #4 organization chop.word sortify }
      if$
    }
    { editor sort.format.names }
  if$
}

% There is a limit, entry.max$, on the length of an entry string variable
% (which is what its sort.key$ is), so we take at most that many characters
% of the constructed key, and hope there aren't many references that match
% to that many characters!

FUNCTION {presort}
#if LAB_ALPH
{ calc.label
  sort.label
  "    "
  *
  type$ "book" =
#else !LAB_ALPH
{ type$ "book" =
#endif LAB_ALPH
  type$ "inbook" =
  or
    'author.editor.sort
    { type$ "proceedings" =
        'editor.organization.sort
        { type$ "manual" =
            'author.organization.sort
            'author.sort
          if$
        }
      if$
    }
  if$
#if LAB_ALPH
  *
#endif LAB_ALPH
  "    "
  *
  year field.or.null sortify
  *
  "    "
  *
  title field.or.null
  sort.format.title
  *
  #1 entry.max$ substring$
  'sort.key$ :=
}

ITERATE {presort}

% And now we can sort

SORT

#endif SORTED

% This long comment applies only to alphabetic labels, when sorted
%
% Now comes the final computation for alphabetic labels, putting in the 'a's
% and 'b's and so forth if required.  This involves two passes: a forward
% pass to put in the 'b's, 'c's and so on, and a backwards pass
% to put in the 'a's (we don't want to put in 'a's unless we know there
% are 'b's).
% We have to keep track of the longest (in width$ terms) label, for use
% by the "thebibliography" environment.
%
% VAR: longest.label, last.sort.label, next.extra: string
%      longest.label.width, last.extra.num: integer
%
% initialize.longest.label ==
%  BEGIN
%       longest.label := ""
%       last.sort.label := int.to.chr$(0)
%       next.extra := ""
%       longest.label.width := 0
%       last.extra.num := 0
%  END
%
% forward.pass ==
%  BEGIN
%       if last.sort.label = sort.label then
%           last.extra.num := last.extra.num + 1
%           extra.label := int.to.chr$(last.extra.num)
%       else
%           last.extra.num := chr.to.int$("a")
%           extra.label := ""
%           last.sort.label := sort.label
%       fi
%  END
%
% reverse.pass ==
%  BEGIN
%       if next.extra = "b" then
%           extra.label := "a"
%       fi
%       label := label * extra.label
%       if width$(label) > longest.label.width then
%           longest.label := label
%           longest.label.width := width$(label)
%       fi
%       next.extra := extra.label
%  END

#if LAB_ALPH

#if SORTED

STRINGS { longest.label last.sort.label next.extra }

INTEGERS { longest.label.width last.extra.num }

FUNCTION {initialize.longest.label}
{ "" 'longest.label :=
  #0 int.to.chr$ 'last.sort.label :=
  "" 'next.extra :=
  #0 'longest.label.width :=
  #0 'last.extra.num :=
}

FUNCTION {forward.pass}
{ last.sort.label sort.label =
    { last.extra.num #1 + 'last.extra.num :=
      last.extra.num int.to.chr$ 'extra.label :=
    }
    { "a" chr.to.int$ 'last.extra.num :=
      "" 'extra.label :=
      sort.label 'last.sort.label :=
    }
  if$
}

FUNCTION {reverse.pass}
{ next.extra "b" =
    { "a" 'extra.label := }
    'skip$
  if$
  label extra.label * 'label :=
  label width$ longest.label.width >
    { label 'longest.label :=
      label width$ 'longest.label.width :=
    }
    'skip$
  if$
  extra.label 'next.extra :=
}

EXECUTE {initialize.longest.label}

ITERATE {forward.pass}

REVERSE {reverse.pass}

#else !SORTED

% It still doesn't seem like a good idea to use an order-of-citation
% reference list when using alphabetic labels, but when this happens we
% must compute the longest label

STRINGS { longest.label }

INTEGERS { longest.label.width }

FUNCTION {initialize.longest.label}
{ "" 'longest.label :=
  #0 'longest.label.width :=
}

FUNCTION {longest.label.pass}
{ label width$ longest.label.width >
    { label 'longest.label :=
      label width$ 'longest.label.width :=
    }
    'skip$
  if$
}

EXECUTE {initialize.longest.label}

ITERATE {longest.label.pass}

#endif SORTED

#else !LAB_ALPH

% Now comes the computation for numeric labels.
% We use either the sorted order or original order.
% We still have to keep track of the longest (in width$ terms) label, for use
% by the "thebibliography" environment.

STRINGS { longest.label }

INTEGERS { number.label longest.label.width }

FUNCTION {initialize.longest.label}
{ "" 'longest.label :=
  #1 'number.label :=
  #0 'longest.label.width :=
}

FUNCTION {longest.label.pass}
{ number.label int.to.str$ 'label :=
  number.label #1 + 'number.label :=
  label width$ longest.label.width >
    { label 'longest.label :=
      label width$ 'longest.label.width :=
    }
    'skip$
  if$
}

EXECUTE {initialize.longest.label}

ITERATE {longest.label.pass}

#endif LAB_ALPH

% Now we're ready to start writing the .BBL file.
% We begin, if necessary, with a LaTeX macro for unnamed names in an alphabetic
% label; next comes stuff from the `preamble' command in the database files.
% Then we give an incantation containing the command
%     \begin{thebibliography}{...}
% where the `...' is the longest label.
%
% We also call init.state.consts, for use by the output routines.

FUNCTION {begin.bib}
#if LAB_ALPH
{ et.al.char.used
    { "\newcommand{\etalchar}[1]{$^{#1}$}" write$ newline$ }
    'skip$
  if$
  preamble$ empty$
#else !LAB_ALPH
{ preamble$ empty$
#endif LAB_ALPH
    'skip$
    { preamble$ write$ newline$ }
  if$
  "\begin{thebibliography}{"  longest.label  * "}" * write$ newline$
}

EXECUTE {begin.bib}

EXECUTE {init.state.consts}

% Now we produce the output for all the entries

ITERATE {call.type$}

% Finally, we finish up by writing the `\end{thebibliography}' command.

FUNCTION {end.bib}
{ newline$
  "\end{thebibliography}" write$ newline$
}

EXECUTE {end.bib}