let s1, s2 be State of SCMPDS ; for I being parahalting Program of SCMPDS st Initialize (stop I) c= s1 & Initialize (stop I) c= s2 & s1,s2 equal_outside NAT holds
( LifeSpan (ProgramPart s1),s1 = LifeSpan (ProgramPart s2),s2 & Result (ProgramPart s1),s1, Result (ProgramPart s2),s2 equal_outside NAT )
let I be parahalting Program of SCMPDS ; ( Initialize (stop I) c= s1 & Initialize (stop I) c= s2 & s1,s2 equal_outside NAT implies ( LifeSpan (ProgramPart s1),s1 = LifeSpan (ProgramPart s2),s2 & Result (ProgramPart s1),s1, Result (ProgramPart s2),s2 equal_outside NAT ) )
set SI = stop I;
assume that
A1:
Initialize (stop I) c= s1
and
A2:
Initialize (stop I) c= s2
and
A3:
s1,s2 equal_outside NAT
; ( LifeSpan (ProgramPart s1),s1 = LifeSpan (ProgramPart s2),s2 & Result (ProgramPart s1),s1, Result (ProgramPart s2),s2 equal_outside NAT )
A4:
ProgramPart s2 halts_on s2
by A2, SCMPDS_4:63;
A5:
ProgramPart s1 halts_on s1
by A1, SCMPDS_4:63;
A6:
now let l be
Element of
NAT ;
( CurInstr (ProgramPart s2),(Comput (ProgramPart s2),s2,l) = halt SCMPDS implies LifeSpan (ProgramPart s1),s1 <= l )assume A7:
CurInstr (ProgramPart s2),
(Comput (ProgramPart s2),s2,l) = halt SCMPDS
;
LifeSpan (ProgramPart s1),s1 <= l
CurInstr (ProgramPart s1),
(Comput (ProgramPart s1),s1,l) = CurInstr (ProgramPart s2),
(Comput (ProgramPart s2),s2,l)
by A1, A2, A3, Th20;
hence
LifeSpan (ProgramPart s1),
s1 <= l
by A5, A7, AMI_1:def 46;
verum end;
CurInstr (ProgramPart s2),(Comput (ProgramPart s2),s2,(LifeSpan (ProgramPart s1),s1)) =
CurInstr (ProgramPart s1),(Comput (ProgramPart s1),s1,(LifeSpan (ProgramPart s1),s1))
by A1, A2, A3, Th20
.=
halt SCMPDS
by A5, AMI_1:def 46
;
hence
LifeSpan (ProgramPart s1),s1 = LifeSpan (ProgramPart s2),s2
by A6, A4, AMI_1:def 46; Result (ProgramPart s1),s1, Result (ProgramPart s2),s2 equal_outside NAT
then A8:
Result (ProgramPart s2),s2 = Comput (ProgramPart s2),s2,(LifeSpan (ProgramPart s1),s1)
by A4, AMI_1:122;
Result (ProgramPart s1),s1 = Comput (ProgramPart s1),s1,(LifeSpan (ProgramPart s1),s1)
by A5, AMI_1:122;
hence
Result (ProgramPart s1),s1, Result (ProgramPart s2),s2 equal_outside NAT
by A1, A2, A3, A8, Th20; verum