Wierd expression in Maple ; $min(0, signum(x^2+y^2)*\infty)$

Question

Im getting this as return in Maple;

$min(0, signum(x^2+y^2)*\infty)$

What is it suppose to mean?

Its in the answer of the follwoing;

minimize(P(x, y, z, w);

2 min(0, signum(x^2+y^2)infinity + min(-6 x, 6 x)

+ min(-6 y, 6 y) + min(-6 z, 6 z) + min(-6 w, 6 w) + C y w

+ C x z - D x z - D y z

P is a polynomial in 4 variables x,y,z,w and with some constraints on the coefficients.

Answer 1

It's a weakness. My guess is that the answer will come out fine if you first do

assume(x::real,y::real, z::real, w::real);

What it means is that you need to either add a factor of 0 to the answer when signum(x^2+y^2) is 1 (which it essentially always is); if x^2+y^2 could even be $< 0$, then this would evaluate to $-\infty$.