Re: [Epigram] zero not suc

2005-06-24 Thread Conor McBride
Thorsten Altenkirch wrote: Can you complete that proof? Yes, ( n : Nat ! let !--! ! zeronosuc n : not (zero = suc n) ) zeronosuc n => znosuc n That's not entirely facetious. You can only do 'pattern matching' on the

Re: [Epigram] zero not suc

2005-06-24 Thread Thorsten Altenkirch
can you tell me why the second attempt to prove that zero is not a succ fails? There are several levels of explanation. First of all, if you have a look at the syntax, e.g. section 3 of http://www.dur.ac.uk/CARG/epigram/epigram-system.pdf (no idea why this is still in Durham), you find that t

[Epigram] zero not suc

2005-06-23 Thread Venanzio Capretta
Hi, can you tell me why the second attempt to prove that zero is not a succ fails? Can you complete that proof? Cheers, Venanzio -- Venanzio Capretta Department of Mathematics and Statistics University of Ottawa, Canada http://www.science.uottawa.ca/~vcapr396/ ---