Re: [Maxima-discuss] bad simp of acos, conjugate(acos..) was Re: sub expression with missing simp flags.

[Raymond T. <toy...@gm...>]

    Richard> I discovered.....

    Richard> There is a really terrible something going on with
    Richard> simplification of acos, though.

    Richard> do this
    Richard>     :lisp (trace simplifier)
    Richard>     acos(z)

I don't see an simplifier function.  Did you mean something else?
simplifya?

    Richard> you can see the simplifier being called many many times, on
    Richard> expressions like 3^(1/2)/2 expressions not involving z at
    Richard> all.

Perhaps because simp-%acos looks for special args?  acos(sqrt(3)/2) is a
something that we'd want to be simplified to %pi/6.

Maybe the code for this should check to see if the arg is an atom (and
not +/-1) and bypass all the tests for special args?  That would
slightly speed up things like acos(z).