integrate(atan(y),y,x,inf) loops endlessly



I have observed the reported bug working on the code of $laplace. If we
correct a bug in the lisp function createname we get a lot of more
integrals with $laplace.

I have done some further improvements and added the code to call
$specint when $laplace fails. Next I have tried the modified $laplace
function with all integrals of the test file rtest_hypgeo.mac.

With the modifications up to now almost all integrals can be solved
calling $laplace too.

But some types of integrals do not work. $laplace does not return from a
call. 

One reason I have found is that the integral in the bug report does not
work. $laplace has an recursive integration algorithm which is called
for some types of integrals. The reported integral is generated
internally in this recursive algorithm.

Dieter Kaiser