Function: idealval
Section: number_fields
C-Name: idealval
Prototype: lGGG
Help: idealval(nf,x,pr): valuation at pr given in idealprimedec format of the
 ideal x in the number field nf.
Doc: gives the valuation of the ideal $x$ at the prime ideal \var{pr} in the
 number field $\var{nf}$, where \var{pr} is in \kbd{idealprimedec} format.
