You just need to learn to use the rules for placing T's and F's under the columns with ~, ^, v, →, ↔ Rules for putting T or F: ~T becomes F, ~F becomes T T^T becomes T, anything else with ^ becomes F FvF becomes F, anything else with v becomes T T→F becomes F, anything else with → becomes T T↔T, F↔F both become T, anything else with ↔ becomes F Now you fill in the missing T's, F's by the rules above I've filled the T's and F's under the columns for the single letters p, q, r. 1. ~(p^q) p | q | p^q | ~(p^q) | T | T | | | T | F | | | F | T | | | F | F | | | 2. ~pv~q p | q | ~p | ~q | ~pV~q) | T | T | | | | T | F | | | | F | T | | | | F | F | | | | 3. (p^q)→(pV~q) p | q | r | ~q | p^q | pV~q | (P^q)→(pV~q) | T | T | T | | | | | T | T | F | | | | | T | F | T | | | | | T | F | F | | | | | F | T | T | | | | | F | T | F | | | | | F | F | T | | | | | F | F | F | | | | | 4. ~q→(p↔r) p | q | r | ~q | p↔r | ~q→(p↔r) | T | T | T | | | | T | T | F | | | | T | F | T | | | | T | F | F | | | | F | T | T | | | | F | T | F | | | | F | F | T | | | | F | F | F | | | | Edwin