[m-dev.] user-defined equality on equivalence types

[Peter Schachte]

In case the Davids' replies aren't convincing enough, here's a practical
argument.  Try writing a simple equality pred.  Say, define smallint == int,
and then define equality on smallint to be equality modulo 256.  Something
like that.  I think you'll find it difficult without causing an infinite
recursion or resorting to writing it in C.

-- 
Peter Schachte                     In large states public education will
mailto:schachte at cs.mu.OZ.AU        always be mediocre, for the same reason
http://www.cs.mu.oz.au/~schachte/  that in large kitchens the cooking is
Phone:  +61 3 8344 9166            usually bad.
Fax:    +61 3 9348 1184                -- Nietzsche 
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