reserve m for Nat;
reserve P for Instruction-Sequence of SCM+FSA;

theorem Th6:
  for a,b,c being Int-Location holds a <> b implies
   b := c does not destroy a
proof
  let a,b,c be Int-Location;
  assume
A1: a <> b;
  now
    let e be Int-Location;
    let l be Element of NAT;
    let f be FinSeq-Location;
    thus a := e <> b := c by A1,SF_MASTR:1;
A2: InsCode (b := c) = 1 by SCMFSA_2:18;
    hence AddTo(a,e) <> b := c by SCMFSA_2:19;
    thus SubFrom(a,e) <> b := c by A2,SCMFSA_2:20;
    thus MultBy(a,e) <> b := c by A2,SCMFSA_2:21;
    thus Divide(a,e) <> b := c & Divide(e,a) <> b := c by A2,SCMFSA_2:22;
    thus a :=(f,e) <> b := c by A2,SCMFSA_2:26;
    thus a :=len f <> b := c by A2,SCMFSA_2:28;
  end;
  hence thesis;
end;
