Re: [Help-glpk] how to use prod?

[Andrew Makhorin]

> I am trying to use prod to calculate the production of numbers
> stored in an array x.
> 
> I wrote: prod {i in 1..5} x[i];    // same format with sum
> 
> but I was told  "integrand following prod{...} has invalid type". 
> 
> it seems there is sth wrong with x[i]. (if i use i, everything will
> be fine.)
> 
> anybody know this?

The error happens because x[i] is a variable. You cannot use
non-linear constraints in MathProg.