Function: serprec
Section: conversions
C-Name: gpserprec
Prototype: Gn
Help: serprec(x,v):
 return the absolute precision x with respect to power series in the variable v.
Doc: returns the absolute precision of $x$ with respect to power series
 in the variable $v$; this is the
 minimum precision of the components of $x$. The result is \tet{+oo} if $x$
 is an exact object (as a series in $v$):
 \bprog
 ? serprec(x + O(y^2), y)
 %1 = 2
 ? serprec(x + 2, x)
 %2 = +oo
 ? serprec(2 + x + O(x^2), y)
 %3 = +oo
 @eprog

Variant: Also available is \fun{long}{serprec}{GEN x, GEN p}, which returns
 \tet{LONG_MAX} if $x = 0$, otherwise the series precision as a \kbd{long} integer.
