Thanks for your replies.<div><br></div><div>In particular to Jon for the reference to the Haskell 98 standard and the comment about language design.</div><div><br></div><div>If anyone has further references to Haskell 98 or Erlang, I'm still interested.</div>
<div><br></div><div>Regarding cost, I do see the difference in factors (Integer - Int, and computable real - Double) as being relevant, but not necessarily a show-stopper.</div><div><br></div><div>Regarding co-semidecidable equality, I'll just note that any numerical analyst knows that you're not allowed to compare for equality in Double either. Rationals or the real algebraic closure do have decidable equality but are, as far as I know, even more costly to compute with.</div>
<div><br></div><div>Thanks,</div><div>Jens</div><div><br></div><div><br></div><div><br></div>