Their statement affirms: "if it makes my dick hard, then it's a woman" whereas the assumption being made here is "if it's a woman, then it makes my dick hard". This is the converse of the original statement, and doesn't carry the same logical truth as the original.
It should be noted that the inverse ("if it doesn't make my dick hard, then it isn't a woman") also doesn't, but the contrapositive ("if it's not a woman, it doesn't make my dick hard") does!
Are you gonna teach proofs by induction next week?
That's a lot of words to say "sufficient, but not necessary. "
By this logic, the math problem the teacher called me up to the board to solve in 10th grade when I had a random boner was also a woman.
God damn gusts of wind women
The scalene triangle
Ah yes, the most erotic of all triangles