Dear Fred, A good answer, but my point was that it was a bad question. You see this once you start pressing at the details. Are seals and turtles fish? No, but on your definition it depends on whether flippers count as legs or not. What about sea snakes? Obviously not - they're snakes, that just happen to live in the sea. But then eels do seem a bit more fishy. A meticulous zoologist would start piling on the subclauses to pin it down more precisely, but we know that that does not actually refine our understanding of zoology. It just amplifies the misconceptions underlying the original question. I'm saying the same can happen in mathematics. All the best, Steve.
On 11 Feb 2017, at 20:42, Fred E.J. Linton <fejlinton@usa.net> wrote:
Steve, et al.,
If you want
a definition of "fish", but on the understanding that it has to include whales
let me offer: "legless marine vertebrates" :-) .
Cheers, -- tlvp
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