Question

If p→q is true, then ~q→~p is true? True or False

Answer 1

true i think

Answer 2

true

Answer 3

yes it is true

Answer 4

the question is then, why would it be true?

Answer 5

there are 3 definitions that i can recall from this material

inverse: p -> q ::: -p -> -q

converse: p -> q ::: q -> p

i always feel these two are backwards ....

the third is

contrapositive: p -> q ::: -q -> -p

a contrapositive ALWAYS has the same truth value

Answer 6

... always retains the same truth value? maintains the same truth value? .... if one side is true the other side is true :)