theorem
  M1 c= N & M2 c= N implies 0.M1 = 0.M2 & 0.M1 in M2 & (the carrier of
  M1 c= the carrier of M2 implies M1 c= M2) & ((for n st n in M1 holds n in M2)
implies M1 c= M2) & (the carrier of M1 = the carrier of M2 & M1 is strict & M2
  is strict implies M1 = M2) & (0).M1 c= M2
by VECTSP_4:12,VECTSP_4:18,VECTSP_4:27,VECTSP_4:28,VECTSP_4:29,VECTSP_4:40;
