Here is one solution: Ltac mt PtoQ notQ notP := match type of PtoQ with | ?P -> _ => pose proof ((fun p => notQ (PtoQ p)) : ~ P) as notP end ... ... <看更多>

Modus ponens rule is : from P→Q and P, infer Q. This rule correspond to the soundness of the "argument" : P→Q,P⊨Q. where an argument is sound when, ... ... <看更多>