comparison with wildcard raises error

[dkrenn]

sage: w = SR.wild()
sage: {a*w+b: 0 for a in [1, 2] for b in [1, 2]}

results in a TypeError

...
TypeError: ECL says: THROW: The catch MACSYMA-QUIT is undefined.

This seems to be a problem with comparison as:

sage: w = SR.wild()
sage: bool(w == 1)

results in the same error.

Component: symbolics

Issue created by migration from https://trac.sagemath.org/ticket/21070

[rwst]

comment:1

Up to now noone thought about what happens if wildcards are compared. That Python's dictcomp calls Expression.__nonzero__ is problematic is nothing, new but it was just a performance problem. Now we need to make sure in the Maxima interface that no wildcards slip through.

[rwst]

comment:2

Better still, in __nonzero__ check early for wildcards in equations and use (lhs-rhs).is_trivial_zero().