Kilt, Skirt, MUG, etc.

[jkdesq]

All oranges are fruit.

Not all fruit is oranges.

All kilts are skirts.

Not all skirts are kilts.

I disagree and so does the OED. As the OED defines a "skirt" as a garment for woman, the only kilt fitting within the OED's definition of "skirt" is a woman's kilt.

A man's kilt is not a skirt. I guess to put it into your parlance, a man's kilt is not a fruit but a vegetable.