Function: Colrev
Section: conversions
C-Name: gtocolrev0
Prototype: GD0,L,
Help: Colrev(x, {n}): transforms the object x into a column vector of
 dimension n in reverse order with respect to Col(x, {n}). Empty vector if x
 is omitted.
Description:
 (gen):vec     gtocolrev($1)
Doc:
 as $\kbd{Col}(x, -n)$, then reverse the result. In particular,
 \kbd{Colrev} is the reciprocal function of \kbd{Polrev}: the
 coefficients of the vector start with the constant coefficient of the
 polynomial and the others follow by increasing degree.
Variant: \fun{GEN}{gtocolrev}{GEN x} is also available.
