let s be State of ; for I being No-StopCode Program of st Initialized (stop I) c= s & I is_halting_on s & card I > 0 holds
LifeSpan s > 0
let I be No-StopCode Program of ; ( Initialized (stop I) c= s & I is_halting_on s & card I > 0 implies LifeSpan s > 0 )
set II = Initialized (stop I);
set si = s +* (Initialized (stop I));
assume that
A1:
Initialized (stop I) c= s
and
A2:
I is_halting_on s
and
A3:
card I > 0
; LifeSpan s > 0
A4:
s = s +* (Initialized (stop I))
by A1, FUNCT_4:79;
assume
LifeSpan s <= 0
; contradiction
then A5:
LifeSpan s = 0
;
A6:
I c= Initialized (stop I)
by SCMPDS_6:17;
then A7:
dom I c= dom (Initialized (stop I))
by GRFUNC_1:8;
A8:
inspos 0 in dom I
by A3, SCMPDS_4:1;
ProgramPart (s +* (Initialized (stop I))) halts_on s +* (Initialized (stop I))
by A2, SCMPDS_6:def 3;
then halt SCMPDS =
CurInstr (Computation (s +* (Initialized (stop I))),0 )
by A4, A5, AMI_1:def 46
.=
CurInstr (s +* (Initialized (stop I)))
by AMI_1:13
.=
s . (inspos 0 )
by A4, SCMPDS_6:21
.=
(Initialized (stop I)) . (inspos 0 )
by A1, A8, A7, GRFUNC_1:8
.=
I . (inspos 0 )
by A8, A6, GRFUNC_1:8
;
hence
contradiction
by A8, SCMPDS_5:def 3; verum