Gerhard
Gentzen
(µ¶ÀÏ ¼öÇÐÀÚ ³í¸®ÇÐÀÚ 1909~1945)
Gerhard Gentzen Àº µ¶ÀÏ¿¡¼ ž üÄÚÀÇ ÇÁ¶óÇÏ
Æ÷·Î¼ö¿ë¼Ò¿¡¼ ·¯½Ã¾ÆÀο¡ ÀÇÇØ ³ªÂî¿¡ Ãæ¼ºÇÑ °æ·ÂÀ¸·Î üÆ÷µÇ¾î Á×¾ú´Ù.
1929 ¿¡¼ 1933 ³â±îÁö University of Göttingen
¿¡ ÀÖÀ¸¸é¼ ÁÖ·Î foundations of mathematics, in proof theory, specifically natural deduction
and the sequent
calculus ¸¦ ¿¬±¸Çß´Ù. ±×ÀÇ cut-elimination theorem Àº proof-theoretic semantics
ÀÇ ÀÌÁ¤Ç¥°¡ µÇ¾úÀ¸¸ç, ±×ÀÇ "Investigations into Logical Deduction"
¿¡ ´ëÇÑ Ã¶ÇÐÀû ¾ð±ÞÀº Wittgenstein ÀÇ ±Ý¾ð "meaning is use" ¿Í ÇÔ²²
inferential role semantics À» À§ÇÑ Ãâ¹ßÁ¡ÀÌ µÇ¾ú´Ù. ................ (Wikipedia
: Gerhard Gentzen)
term :
³í¸®ÇÐ
(Logic) ¼öÇÐ
(Mathematics) ¿¬¿ª¹ý
(Deduction) Àǹ̷Ð
(Semantics) Ludwig Wittgenstein
Gerhard Gentzen
paper :
- Untersuchungen über das logische Schliessen.
Mathematische Zeitschrift, 1934
- Gentzens Problem: Mathematische Logik im
nationalsozialistischen Deutschland. Eckart Menzler-Trott. Birkhäuser Verlag, 2001
- Collected Papers of Gerhard Gentzen. M. E. Szabo. North-Holland,
1969.
site :
- Gerhard
Gentzen : St
Andrews
- ±¸Á¶ ·ÎÁ÷(constructive logic)ÀÇ ÀÌÇØ: Áõ¸í ½Ã½ºÅÛ°ú ¶÷´Ù °è»ê¹ý(lambda calculi)¿¡ ´ëÇÏ¿©
: Constructive logics Part I: A tutorial on proof systems and
typed lambda-calculi, Jean
Gallier, TCS 110, 1993
....... ¼öÇп¡¼ ¿¬±¸ÇÏ´ø ³í¸®(logic)¸¦ ÇÁ·Î±×·¡¹Ö ¾ð¾î¿¡ Àû¿ëÇÏ´Â (ÇöÀç Ȱ¹ßÇÏ°Ô ¿¬±¸µÇ°í ÀÖ´Â) ¿¬±¸
ºÐ¾ß¸¦ ÀÌÇØÇϱâ À§ÇÏ¿©, ±× ¹è°æÀÌ µÇ´Â ±¸Á¶ ³í¸®(constructive logic)¸¦ »ìÆì º»´Ù. À̹Ì, ÀÌÀüÀÇ ¼¼¹Ì³ª(judaigi)¿¡¼
¹ßÇ¥ÇÏ¿´°í, ¶ÇÇÑ ¹è¹Î¿À ¹Ú»ç´Ô ¼¼¹Ì³ª¿¡¼ ±í°Ô ´Ù·ç¾úÁö¸¸, À§ÀÇ ¹ßÇ¥ ³í¹®À» Åä´ë·Î Çѹø ´õ »ìÆì º»´Ù. ÀÚ¿¬
Ã߷йý(natural deduction)¿¡ ÀÇÇÑ ±¸Á¶ ³í¸® Áõ¸í ½Ã½ºÅÛ°ú GentzenÀÇ ±ÍÃß °è»ê¹ý(sequent calculi)¿¡ ÀÇÇÑ ±¸Á¶
³í¸® Áõ¸í ½Ã½ºÅÛÀÌ Áõ¸íÇÒ ¼ö ÀÖ´Â ¹üÀ§°¡ °°À½À» º¸ÀδÙ. (ÀÚ¿¬ Ã߷йý¿¡ ºñÇØ ±ÍÃß °è»ê¹ýÀº Áõ¸íÀ» ÀÚµ¿ÈÇϱⰡ ½±´Ù.) À̸¦ À§ÇÏ¿© ÀÚ¿¬
Ã߷йýÀÇ ¸ðµç Áõ¸í¿¡ Ç¥ÁØÇü(normal form)ÀÌ ÀÖÀ½À» º¸À̰í, ÀÚ¿¬ Ã߷йýÀÇ Áõ¸íÀ» ±ÍÃß °è»ê¹ý + (cut) ±ÔÄ¢ÀÇ Áõ¸íÀ¸·Î ¹Ù²Ù´Â
¾Ë°í¸®Áò N °ú ±ÍÃß °è»ê¹ýÀ» ÀÚ¿¬ Ã߷йýÀÇ Ç¥ÁØÇü Áõ¸íÀ¸·Î ¹Ù²Ù´Â ¾Ë°í¸®Áò G ¸¦ Á¦½ÃÇÑ´Ù. ¸¶Áö¸·À¸·Î
GentzenÀÇ cut ±ÔÄ¢ Á¦°Å Á¤¸®¸¦ ÅëÇØ, ÀÚ¿¬ Ã߷йýÀÇ Áõ¸í°ú ±ÍÃß °è»ê¹ýÀÌ »óÈ£ º¯È¯ °¡´ÉÇÔÀ» º¸ÀδÙ. .....