Function: Polrev
Section: conversions
C-Name: gtopolyrev
Prototype: GDn
Description:
 (gen,?var):pol  gtopolyrev($1, $2)
Help: Polrev(t,{v='x}): convert t (usually a vector or a power series) into a
 polynomial with variable v, starting with the constant term.
Doc:
 transform the object $t$ into a polynomial
 with main variable $v$. If $t$ is a scalar, this gives a constant polynomial.
 If $t$ is a power series, the effect is identical to \kbd{truncate}, i.e.~it
 chops off the $O(X^k)$.

 The main use of this function is when $t$ is a vector: it creates the
 polynomial whose coefficients are given by $t$, with $t[1]$ being the
 constant term. \tet{Pol} can be used if one wants $t[1]$ to be the leading
 coefficient:
 \bprog
 ? Polrev([1,2,3])
 %1 = 3*x^2 + 2*x + 1
 ? Pol([1,2,3])
 %2 = x^2 + 2*x + 3
 @eprog
 The reciprocal function of \kbd{Pol} (resp.~\kbd{Polrev}) is \kbd{Vec} (resp.~
 \kbd{Vecrev}).
