Of course this makes doing math with diracdelta somewhat harder.
pwint(pwdelta(x-a)*between(x,0,a,closed),x,minf,inf) will be wrong unless I
can find a way to test for continuity at a. I have a function that can do
that but I think it needs work.
Here is the function.
continuousp(__e,__x,__v):=
block(
[_y],
if is(equal(pwlimit(at(__e, [__x=__v+1/_y]), _y, inf), pwlimit(at(__e,
[__x=__v+1/_y]), _y, minf)))=true then true else false
)$
Maybe this can be improved. It is pretty good though, it gets a lot of
cases right. log(x-a), 1/(x-a), unit_step(x-a), signum(x-a), between(x,a,b)
it can't do yet, I need to improve pwlimit.
Rich