theorem Th49:
 (I ';' j).(LastLoc I) = IncAddr(j,LastLoc I)
proof
A1: 0 <= LastLoc Macro j;
   0 in dom Macro j by COMPOS_1:57;
   then
A2: (Macro j)/.0 = (Macro j).0 by PARTFUN1:def 6
       .= j by COMPOS_1:58;
 thus (I ';' j).(LastLoc I) = (I ';' Macro j).(LastLoc I + 0)
      .= IncAddr((Macro j)/.0,LastLoc I) by A1,Th43
      .= IncAddr(j,LastLoc I) by A2;
end;
