想請教高手 1.) Prove A v A v A |- B -> A 下面應該是屬於論述邏輯? (Predicate Logic) 2.) |- (for all x)(A -> B -> C) -> (for all x)(A -> B) -> (for all x)(A -> C) 3.) Prove by induction on terms, that for any terms t and s, if s is a prefix of t, then the strings t and s must be identical. 我承認是問功課.... 但我真的想不出來要怎麼證明?..... 第一題只有一邊有B 是要怎麼搞 Orz..... 題外話 學期快結束了 我還真好奇我怎麼存活到現在 囧.. 感謝各位的幫忙 T_T -- The world ain't all sunshine n rainbows.It's a very mean n nasty place. N it'll beat u to ur knees n keep u there permanently if u let it. You,me or nobody's gon hit as hard as life. But it ain't about how hard u hit. It's about how hard u can get hit;how hard u can take,n keep movin forward.If u know what u'r worth, then go out n get what u'r worth. But u gotta be willing to take the hit, n not pointing fingers saying u ain't where u r becuz of him, or her or anybody. --

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