Function: algdivl
Section: algebras
C-Name: algdivl
Prototype: GGG
Help: algdivl(al,x,y): element x\y in al.
Doc: Given two elements $x$ and $y$ in \var{al}, computes their left quotient
 $x\backslash y$ in the algebra \var{al}: an element $z$ such that $xz=y$ (such
 an element is not unique when $x$ is a zerodivisor). If~$x$ is invertible, this
 is the same as $x^{-1}y$. Assumes that $y$ is left divisible by $x$ (i.e. that
 $z$ exists). Also accepts matrices with coefficients in~\var{al}.
