Re: [Caml-list] Equality of functional values

[Andrej Bauer <Andrej.Bauer@fmf.uni-lj.si>]

Simon Frost wrote:
> I'm trying to use a software package written in ocaml (IBAL), however,
> it fails a test due to 'Fatal error: exception Invalid_argument("equal:
> functional value"). It seems that equality isn't defined for functional
> values in OCAML (although I'm not an expert), so I'm wondering what the
> workaround is.

This may not sound very helpful, but: you are doing something wrong if 
you need to rely on equality of functions. Equality of functions is not 
computable.

A suitable workaround would be to tell us what it is that you are doing, 
and we will tell you what to use instead of functions (if possible). To 
give you an idea of what you I am talking about:

Suppose you came to us and complained that you cannot compare 
polynomials with integer coefficients, and it turned out that you 
represent polynomials as functions. We would then tell you not to do 
that, and represent polynomials as arrays (or lists) of coefficients, or 
objects, or some other data structure that is equipped with decidable 
equality.

Andrej