theorem Th20:
 for k being Nat holds
  for p being finite NAT-defined (the InstructionsF of S)-valued Function
   holds dom Reloc(p,k) = dom Shift(p,k)
proof let k be Nat;
 let p be finite NAT-defined (the InstructionsF of S)-valued Function;
A1: dom IncAddr(p,k) = dom p by Def9;
 thus dom Reloc(p,k)
          = { m+k where m is Nat :m in dom p} by A1,VALUED_1:def 12
         .= dom Shift(p,k) by VALUED_1:def 12;
end;
