Bug in parse_expr with -oo

[Casey S. Schroeder]

Hello Sympy,

It appears there is a bug with the parse_expr running under evaluate(0)

mathystuff = "Union(Interval(-oo,0),Interval(-3,oo))"

with evaluate(0):
    frmla0 = parser.parse_expr(mathystuff, local_dict, transformations=transformations)

the error I am getting appears to be 'cannot determine truthvalue of Relational', which seems to me to mean it does not know how to arrange the terms with -oo without reducing it...  It also fails if I replace oo with 30.  But not if I replace -oo with -30.  Hence the issue appears to be with -oo

I am on 1.10.1 so if I need to update let me know, but it was a recent conda install.

Thanks,

Casey

[Aaron Meurer]

It looks like a bug with the evaluate=False logic. The issue isn't
with parse_expr(). You get the same error running

with evaluate(False):
Union(Interval(-oo,0),Interval(-3,oo))

although I should mention that parse_expr(evaluate=False) ought to
work, but it doesn't. Can you open an issue for this?

Aaron Meurer

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