1. The problem statement, all variables and given/known data Sometimes i got a question with homework if i can prove something. I got a book where the tolled me to use truthtables to see the outcome : For example : (notP V Q) <=> (P => Q) P Q | notP | notP v Q | P=>Q | (notP V Q) <=> (P => Q) 0 0 | 1 | 1 | 1 | 1 0 1 | 1 | 1 | 1 | 1 1 0 | 0 | 0 | 0 | 1 1 1 | 0 | 1 | 1 | 1 Lateron in the same book it's statement is, that it's easier to use the Logic laws then written down the truthtable everytime. And gives the logic laws for example 1. Double complement 2. The morgan 3. Commutative 4 Associative etc etc No my question : When do i know what to use. Do i allways start with Double complement , the morgan , Commutative etc. 3. The attempt at a solution Searched on the internet (Different websites) but i can't find the solution/way. I didnt put the question in this forum post because i want to know the steps to take not the answer.