reserve S for with_non_trivial_Instructions COM-Struct;
reserve i,j,k for No-StopCode Instruction of S,
        I,J,K for MacroInstruction of S;
reserve i1,i2,i3,i4,i5,i6 for No-StopCode Instruction of S;
reserve I,J for non empty NAT-defined finite Function;
reserve I,J for MacroInstruction of S;

theorem Th23:
  I <= I ';' J
 proof
   dom CutLastLoc I misses dom Reloc(J,card I -' 1) by COMPOS_1:18;
  hence CutLastLoc I c= I ';' J by FUNCT_4:32;
 end;
