I'm trying to figure out this assignment I'm doing. The task is to show that a conditional statement is a tautology without using truth tables.
This is the conditional statement: [-p && ( p || q )] -> q
Now Absorption law states that: p && ( p || q ) is equivalent to p
but how about when p is false, does it apply at all or am I dead wrong here?
could I get
-p -> q
this would work, but It would not prove that the statement is a tautology :$