simplify inverse_erf(erf(x))



Incidentally,  the inverse to erf is recorded on the property list of %erf

   (%i75) :lisp(get '%erf '$inverse)
   %INVERSE_ERF

The solve function examines  the property list of %erf to solve things such as

   (%i1) solve(erf(x)=7,x);
   (%o1) [x=inverse_erf(7)]

The general simplifier does not routinely look for inverse on the property list. Actually, the property list mechanism doesn't have a way to check that for  the appropriate domain.

--Barton

________________________________________

Buck Golemon <buck.2019 <at> gmail.com> writes:

> (%i12) solve(erf(x) = erf(y), x);
>
> (%o12)                     [x = inverse_erf(erf(y))]
>