.

> m:=evalm(T(-x[0],-y[0])&*matrix(3,3,[v[1],-v[2],0,v[2],v[1],0,0,0,1])&*S(1,-1)&*matrix(3,3,[v[1],v[2],0,-v[2],v[1],0,0,0,1])&*T(x[0],y[0]));