Function: nfeltval
Section: number_fields
C-Name: nfval
Prototype: lGGG
Help: nfeltval(nf,x,pr): valuation of element x at the prime pr as output by
 idealprimedec.
Doc: given an element $x$ in
 \var{nf} and a prime ideal \var{pr} in the format output by
 \kbd{idealprimedec}, computes their the valuation at \var{pr} of the
 element $x$. The same result could be obtained using
 \kbd{idealval(\var{nf},x,\var{pr})} (since $x$ would then be converted to a
 principal ideal), but it would be less efficient.
