let s be State of SCM+FSA; for I being parahalting good Program of SCM+FSA
for a being read-write Int-Location st not I destroys a & s . (intloc 0) = 1 holds
( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s )
let I be parahalting good Program of SCM+FSA; for a being read-write Int-Location st not I destroys a & s . (intloc 0) = 1 holds
( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s )
let a be read-write Int-Location ; ( not I destroys a & s . (intloc 0) = 1 implies ( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s ) )
assume A1:
not I destroys a
; ( not s . (intloc 0) = 1 or ( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s ) )
assume A2:
s . (intloc 0) = 1
; ( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s )
per cases
( s . a > 0 or s . a <= 0 )
;
suppose A3:
s . a > 0
;
( Times (a,I) is_closed_on s & Times (a,I) is_halting_on s )
Directed (loop (if=0 (a,(Goto 2),(I ';' (SubFrom (a,(intloc 0))))))) = loop (if=0 (a,(Goto 2),(I ';' (SubFrom (a,(intloc 0))))))
by SCMFSA6A:63;
then
Directed (loop (if=0 (a,(Goto 2),(I ';' (SubFrom (a,(intloc 0))))))) is_pseudo-closed_on s
by A1, A2, A3, Th117;
hence
(
Times (
a,
I)
is_closed_on s &
Times (
a,
I)
is_halting_on s )
by A3, Th68;
verum end; end;