Question

If p: All birds fly. What is ~ p?


some birds fly
birds always walk
not all birds fly
none of the above

Answer 1

~p is the opposite of p

it means "not p"

so if p is true, then ~p is false

if p is false, then ~p is true

Answer 2

if p: All birds fly

then ~p: it is not the case that all birds fly

what's another way to state that last sentence above?