#4780 function ldefint

[Barton Willis]

Some issues with:

(defmfun $ldefint (exp var ll ul &aux $logabs ans a1 a2)
  (setq $logabs t ans (sinint exp var)
    a1 (toplevel-$limit ans var ul '$minus)
    a2 (toplevel-$limit ans var ll '$plus))
  (and (member a1 '($inf $minf $infinity $und $ind) :test #'eq)
       (setq a1 (nounlimit ans var ul)))
  (and (member a2 '($inf $minf $infinity $und $ind) :test #'eq)
       (setq a2 (nounlimit ans var ll)))
  ($expand (m- a1 a2)))

Problems:

• The limits from the left and right assume that ll < ul, but the code doesn't check that that this is true. I don't know if a incorrect value due to this assumption.

• There should be logic that detects divergent integrals.

• When sinint returns an integration nounform, the function ldefint returns a difference of limits of indefinite integrals. This assumes that the additive constant in each indefinite integral is the same. This is unlikely to ever cause a bug, but it's wrong.

• The final call to $expand is perverse.

• The &aux variables should be updated.

The testsuite call s ldefint only once--it needs much more testing.