éåè«ãŸãšã
éåãç ç©¶ããæ°åŠã®1åé. set theory
- ðã»ãã/Set: èšç®æ©ç§åŠ
- ðª£ã»ããæ§é
ðªåå
mapping.
äºã€ã®éåãäžãããããšãã«ãäžæ¹ã®éåã®åå ã«å¯Ÿãã仿¹ã®éåã®ãã ã²ãšã€ã®å ãæå®ããŠçµã³ã€ãã察å¿.
æ°åŠã«ãããåœæ°ãå矩 cf. ð颿°(èšç®æ©ç§åŠ).
ðçŽå
åéå. AãšBã®éåã§ A and Bã空ã®å Žå=å ±éããªãå Žåã«äžŠã¹ã.
ããžãã¹ã§çŽååå²=ðMECEãªåå².
ðçŽç©
çŽç©éåãŸãã¯ãã«ã«ãç©, ãŸãã¯åã«ãç©ã(product).
éåã®éãŸãïŒéåæïŒã«å¯ŸããŠåéåããäžã€ãã€å ããšãã ããŠçµã«ãããã®ïŒå ã®æïŒãå ãšããŠæã€æ°ããªéå.
cf. ðçµåããšåéãããŠãâŠ