reserve m,n for Nat,
  a,b for Int_position,
  i,j for Instruction of SCMPDS,
  s,s1,s2 for State of SCMPDS,
  I,J for Program of SCMPDS;

theorem Th4:
  card (I ';' i)= card I + 1
proof
  thus card (I ';' i) = card (I ';' Load i) by SCMPDS_4:def 3
    .=card I+ card (Load i) by AFINSQ_1:17
    .=card I+1 by COMPOS_1:54;
end;
