reserve V for RealLinearSpace,
  u,u1,u2,v,v1,v2,w,w1,x,y for VECTOR of V,
  a,a1,a2,b,b1,b2,c1,c2,n,k1,k2 for Real;
reserve uu,vv for object;

theorem
  uu is Element of CMSpace(V,x,y) iff uu is VECTOR of V;
