Function: algadd
Section: algebras
C-Name: algadd
Prototype: GGG
Help: algadd(al,x,y): element x+y in al.
Doc: Given two elements $x$ and $y$ in \var{al}, computes their sum $x+y$ in
the algebra~\var{al}.
\bprog
? A = alginit(nfinit(y),[-1,1]);
? algadd(A,[1,0]~,[1,2]~)
%2 = [2, 2]~
@eprog
Also accepts matrices with coefficients in \var{al}.