Function: rnfidealmul
Section: number_fields
C-Name: rnfidealmul
Prototype: GGG
Help: rnfidealmul(rnf,x,y): relative version of idealmul, where rnf is a
 relative numberfield.
Doc: $\var{rnf}$ being a relative number
 field extension $L/K$ as output by \kbd{rnfinit} and $x$ and $y$ being ideals
 of the relative extension $L/K$ given by pseudo-matrices, outputs the ideal
 product, again as a relative ideal.
