I have check in the code to handle the realpart and the imagpart of the Bessel
functions more general and correct. I hope this is useful and might be a first
step to support more functions.
There are some points to remark:
1.
Maxima no longer returns the default real result for the Bessel functions. E.g.
realpart(bessel_j(n,x)) --> gives the noun form, because in general the result
can be complex. But when we declare n to be an integer we get again the correct
pure real result.
2.
Because abs and cabs uses the algorithm of risplit, the results of these
functions change too and are more correct.
3.
realpart and imagpart are not simplifying functions. This is the reason that we
do not get the most simple results when the Bessel functions are involved in
expressions.
Dieter Kaiser