let a, b, c be Int-Location ; :: thesis: ( a <> b implies b := c does_not_destroy a )
assume A1: a <> b ; :: thesis: b := c does_not_destroy a
now
let e be Int-Location ; :: thesis: for l being Instruction-Location of SCM+FSA
for f being FinSeq-Location holds
( a := e <> b := c & AddTo a,e <> b := c & SubFrom a,e <> b := c & MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )

let l be Instruction-Location of SCM+FSA ; :: thesis: for f being FinSeq-Location holds
( a := e <> b := c & AddTo a,e <> b := c & SubFrom a,e <> b := c & MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )

let f be FinSeq-Location ; :: thesis: ( a := e <> b := c & AddTo a,e <> b := c & SubFrom a,e <> b := c & MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )
thus a := e <> b := c by A1, SF_MASTR:5; :: thesis: ( AddTo a,e <> b := c & SubFrom a,e <> b := c & MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )
A2: ( 1 <> 2 & 1 <> 3 & 1 <> 4 & 1 <> 5 & 1 <> 9 & 1 <> 11 & InsCode (b := c) = 1 ) by SCMFSA_2:42;
hence AddTo a,e <> b := c by SCMFSA_2:43; :: thesis: ( SubFrom a,e <> b := c & MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )
thus SubFrom a,e <> b := c by A2, SCMFSA_2:44; :: thesis: ( MultBy a,e <> b := c & Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )
thus MultBy a,e <> b := c by A2, SCMFSA_2:45; :: thesis: ( Divide a,e <> b := c & Divide e,a <> b := c & a := f,e <> b := c & a :=len f <> b := c )
thus ( Divide a,e <> b := c & Divide e,a <> b := c ) by A2, SCMFSA_2:46; :: thesis: ( a := f,e <> b := c & a :=len f <> b := c )
thus a := f,e <> b := c by A2, SCMFSA_2:50; :: thesis: a :=len f <> b := c
thus a :=len f <> b := c by A2, SCMFSA_2:52; :: thesis: verum
end;
hence b := c does_not_destroy a by Def3; :: thesis: verum