SOLUTION: Proof for: P -> Q Therefore ~Q -> ~P

Question 474140: Proof for:
P -> Q Therefore ~Q -> ~P
Answer by Edwin McCravy(20056) (Show Source): You can put this solution on YOUR website!

 P -> Q Therefore ~Q -> ~P

P  Q  (P -> Q)  ~Q  ~P  (~Q->~P) 
T  T     T       F   F      T
T  F     F       T   F      F
F  T     T       F   T      T
F  F     T       T   T      T

They have the same truth table TFTT



Edwin

RELATED QUESTIONS
What is the proof for ((P→Q)→Q)→(P∨Q) (answered by drk)

solve for q:... (answered by Alan3354)

solve the proof ~F > ~G, P > ~Q, ~F v P, (~G v ~Q) > (L • M), therefore,... (answered by Edwin McCravy)

What is the Formal Proof for P v (Q ^... (answered by lynnlo)

q=p-q/2, for... (answered by stanbon)

I need help completing this proof. 1. R&S, S->(P->Q), Q->P |- P<->Q (answered by solver91311)

Simplify p(p - q) - q(q -... (answered by Fombitz,fractalier)

find the proof of the following: P & Q, P -> R |- R & Q (P v Q) -> R |- ~R->... (answered by Edwin McCravy)

q+r/q+p (answered by Alan3354)