@pmalynin, you forgot the safety variable.
p | q | p ∧ q → ¬q
--+---+-----------
T | T | F You can't be safe and own a gun.
T | F | T You can be safe and not own a gun.
F | T | T You can be unsafe and own a gun.
F | F | T You can be unsafe and not own a gun.
@rwjwjuwjudf, logical implication is correct - logical equivalence leads to this trainwreck: p | q | p ∧ q ↔ ¬q
--+---+-----------
T | T | F You can't be safe and own a gun.
T | F | F You can't be safe and not own a gun.
F | T | T You can be unsafe and own a gun.
F | F | F You can't be unsafe and not own a gun.