{\rtf1\mac\deff2 {\fonttbl{\f0\fswiss Chicago;}{\f2\froman New York;}{\f3\fswiss Geneva;}{\f4\fmodern Monaco;}{\f6\fdecor London;}{\f8\fdecor San Francisco;}{\f11\fnil Cairo;}{\f12\fnil Los Angeles;}{\f13\fnil Zapf Dingbats;}{\f14\fnil Bookman;} {\f16\fnil Palatino;}{\f18\fnil Zapf Chancery;}{\f20\froman Times;}{\f21\fswiss Helvetica;}{\f22\fmodern Courier;}{\f23\ftech Symbol;}{\f24\fnil Mobile;}{\f33\fnil Avant Garde;}{\f34\fnil New Century Schlbk;}{\f101\fnil Wartburg;}{\f118\fnil Warwick S;} {\f128\fnil Moscow;}{\f129\fnil Russian;}{\f135\fnil MATH-BES;}{\f140\fnil Lovell;}{\f149\fnil Detroit;}{\f171\fnil XB Futura ExtraBold;}{\f176\fnil H Futura Heavy;}{\f201\fnil ¡Math;}{\f512\fnil Alexandrie;}{\f2500\fnil Konstanz;}} {\colortbl\red0\green0\blue0;\red0\green0\blue255;\red0\green255\blue255;\red0\green255\blue0;\red255\green0\blue255;\red255\green0\blue0;\red255\green255\blue0;\red255\green255\blue255;}{\stylesheet{\sbasedon222\snext0 Normal;}}{\info{\title DOmartin-lof.rtf}{\author Centre International de Rencontres Mathematiques}}\paperw11880\paperh16820\margl1701\margr1701\margt1417\margb1417\deftab709\widowctrl\ftnbj\makebackup \sectd \linemod0\linex0\headery1077\footery1077\cols1\colsx709\endnhere \pard\plain \qc\sl360 {\b\f16 MIGHT THERE EXIST ABSOLUTELY UNDECIDABLE PROPOSITIONS ?\par \par Per Martin-L\'9af\par }\pard \sl360 {\b\f16 \par }\pard \qc\sl360 {\b\f16 Department of Mathematics, University of Stockholm\par 106 91 Stockholm, Sweden\par }\pard \sl360 {\b\f16 \par }{\f16 \par }{\b\f16\ul Abstract\par }{\f16 \par }\pard \sl360 {\f16 No, there are no absolutely undecidable propositions. The purpose of my talk is to explain why.\par }\pard \par }