Function: idealval
Section: number_fields
C-Name: gpidealval
Prototype: GGG
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.
 The valuation of the $0$ ideal is \kbd{+oo}.
Variant: Also available is
 \fun{long}{idealval}{GEN nf, GEN x, GEN pr}, which returns
 \tet{LONG_MAX} if $x = 0$ and the valuation as a \kbd{long} integer.
