by ohthatpatrick Thu Aug 01, 2013 2:01 pm
You are correct about the contrapositive:
VSm --> WNm
turns into
WNf --> VSf
It's always a good idea, when you're dealing with a binary concept like male/female to switch to the other side of the binary, rather than writing a negation.
In English,
WNf --> VSf
is a much better way to write that contrapositive than
~WNm --> ~VSm
BUT, it would be incorrect to think that VS and WN will always have a gender match. If we have VSf and WNm, neither rule is broken.
Hope this helps.