How can i write A /\ B (A and B) using only the signs for negation and the sign for if then (the right facing arrow)
I know i am supposed to use the changing laws but i cant figure out how.
Regards
$\displaystyle \neg( A \Rightarrow B ) \Longleftrightarrow A \wedge \neg B$ --- you can check this with table of truth ( i think that is the term in english, maybe not ( it is just literal translation from my language ) )
so
you need $\displaystyle A \wedge B \Longleftrightarrow A \wedge \neg(\neg B) \Longleftrightarrow \neg( A \Rightarrow \neg B ) $
what a mistake!!!