#843 1-arg limit: limit(a*inf-inf) => minf

[Stavros Macrakis]

assume(a>1)$
limit(a*inf-inf) => minf

Should be inf assuming the inf's represent the same
variable (limit's usual behavior here). Should be und
if they represent different variables.

[Dan Gildea]

in limit.lisp rev 1.82:

(%i1) assume(a>1);
(%o1) [a > 1]
(%i2) limit(a*inf-inf);
(%o2) minf + inf