let s1, s2 be State of SCM+FSA ; for I, J being Program of SCM+FSA st DataPart s1 = DataPart s2 holds
s1 +* (I +* (Start-At 0 ,SCM+FSA )),s2 +* (J +* (Start-At 0 ,SCM+FSA )) equal_outside NAT
let I, J be Program of SCM+FSA ; ( DataPart s1 = DataPart s2 implies s1 +* (I +* (Start-At 0 ,SCM+FSA )),s2 +* (J +* (Start-At 0 ,SCM+FSA )) equal_outside NAT )
assume A1:
DataPart s1 = DataPart s2
; s1 +* (I +* (Start-At 0 ,SCM+FSA )),s2 +* (J +* (Start-At 0 ,SCM+FSA )) equal_outside NAT
set S2 = s2 +* (J +* (Start-At 0 ,SCM+FSA ));
set S1 = s1 +* (I +* (Start-At 0 ,SCM+FSA ));
A2:
IC (s1 +* (I +* (Start-At 0 ,SCM+FSA ))) = 0
by FUNCT_4:26, SF_MASTR:67;
A3:
IC (s2 +* (J +* (Start-At 0 ,SCM+FSA ))) = 0
by FUNCT_4:26, SF_MASTR:67;
DataPart (s1 +* (I +* (Start-At 0 ,SCM+FSA ))) =
DataPart s1
by SCMFSA8A:11
.=
DataPart (s2 +* (J +* (Start-At 0 ,SCM+FSA )))
by A1, SCMFSA8A:11
;
hence
s1 +* (I +* (Start-At 0 ,SCM+FSA )),s2 +* (J +* (Start-At 0 ,SCM+FSA )) equal_outside NAT
by A2, A3, SCMFSA8A:6; verum