As far as I know so far Axiom just uses the underlying lisp values from cos and acos.
I don't consider it a bug but I don't consider it "stable" either. All other values of all other functions seem to give the same result and that result matches the input in this case. It's a curious result though. I'd expect that they are using Chebyshev polynomials and I'd have expected a symmetric result. Somebody clearly "optimized" the world by saving an instruction somewhere. The problem arose trying to explain a failing case in the regression tests. Now that I understand it better it's not an issue. Tim _______________________________________________ Axiom-developer mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/axiom-developer
