Hello, I have some questions about the truth tables for impliocation and equivalence. for implication we have: p | q | p=> q T | T | T T | F | F F | T | T F | F | T Here I do not understand the last two lines, how can we say that p implies q when p is false, and q is either true or false, if we only know that p is false and q is true, shouldn't p=> be unknown instead of T? The same for p is false and q is false?, shouldn't p=>q then be unknown. I have the same problem for equivalence: p | q | p<=> q T | T | T T | F | F F | T | F F | F | T Here I only have the problem with the last line when both p and q are false. How can we then say that p implies q?