> < ^ Date: Mon, 28 Jul 2003 13:32:25 +0100 (BST)
> < ^ From: Derek Holt <dfh@maths.warwick.ac.uk >
> ^ Subject: Testing expression for positivity

Dear GAP Forum,

(I sent this message early in July, but I did not see it appear in the
GAP Forum, so apologies if it appears twice!)

I have an expression, z,  say, involving the n-th roots of unity E(n), which
evaluates to a real number (i.e. ComplexCojugate(z) = z.) For example
z := E(5) + E(5)^-1 + E(3) + E(3)^-1;

Is there any way to test within GAP whether z is greater than 0, numerically?

Derek Holt.

Miles-Receive-Header: reply

> < [top]