The general simplifier currently treats the various non-

standard objects (inf, minf, und, ind, infinity) as though

they were ordinary variables.

This leads to incorrect results (inf-inf => 0, inf*0 => 0),

incomplete simplification (inf^3 doesn't simplify, though

inf is always correct), and non-canonical representations

(-minf doesn't simplify to inf).

It also seems to me that minf should be represented

uniformly as -inf, not as a special case.

Special-casing these objects in the general simplifier will

add a very small overhead to all simplifications.

The case that reminded me of this problem is abs(minf)

=>-minf.