The routine "expc.s" is a modified version of the routine 
"s3/exp.s". it is here so that it is distributed with the other
function sources.

The only difference is that it fixes a bug in exp such that certain
argument values that should return zero don't.

see  ../test/testexp.s
when using the old /lib/liba.a version of exp it will print
a non-zero value where there should be a zero. I recommend that
expc.s be put into /lib/liba.a as well in place of exp.o
