out jj;

%s:=solve({-b*r12/r11 + c -1, -c*r21/r22 + b -1},{b,c});

%ss:=part(s,1);
%b:=rhs(part(ss,1));
%c:=rhs(part(ss,2));
%a:=-b*r12/r11;
%d:=-c*r21/r22;
a:=mat((0,a,b),(0,c,d),(-1,f,g));
1/a;

shut jj;
bye;
end;