Denying the antecedent with P and Q:
P → Q
~P
Therefore ~Q
Affirming the consequent with ~Q and ~P
~Q → ~P
Wow, I feel kind of bad just writing those chains of “deduction”. Anyways, the same result was concluded from the same minor premise, the only difference is the major premise, and P → Q and ~Q → ~P are equivalent.
edit: formatting
Denying the antecedent with P and Q:
P → Q
~P
Therefore ~Q
Affirming the consequent with ~Q and ~P
~Q → ~P
~P
Therefore ~Q
Wow, I feel kind of bad just writing those chains of “deduction”. Anyways, the same result was concluded from the same minor premise, the only difference is the major premise, and P → Q and ~Q → ~P are equivalent.
edit: formatting