Heron Suit

[Dave Britten]

(05-30-2015 07:02 PM)Gerald H Wrote:  Yes, you're parsing wrong.

"Unless" is "If not" so

No cats have tails unless they have whiskers

is

Only if cats have whiskers then they have tails

or if you like

Whiskers == tails.

Well then that's an even more direct contradiction to say "tail iff whiskers", since he says...

Quote:...has a tail, has no whiskers...

...and says that meshes with all of the first five statements.

I was interpreting it as "no cats have tails, unless of course they have whiskers, in which case it's okay to have a tail", i.e. tail -> whiskers, or conversely, !whiskers -> !tail.