let P1, P2 be Instruction-Sequence of SCMPDS; for s1, s2 being 0 -started State of SCMPDS
for I being Program of SCMPDS st I is_closed_on s1,P1 & I is_halting_on s1,P1 & stop I c= P1 & stop I c= P2 & ex k being Element of NAT st Comput (P1,s1,k) = s2 holds
Result (P1,s1) = Result (P2,s2)
let s1, s2 be 0 -started State of SCMPDS; for I being Program of SCMPDS st I is_closed_on s1,P1 & I is_halting_on s1,P1 & stop I c= P1 & stop I c= P2 & ex k being Element of NAT st Comput (P1,s1,k) = s2 holds
Result (P1,s1) = Result (P2,s2)
let I be Program of SCMPDS; ( I is_closed_on s1,P1 & I is_halting_on s1,P1 & stop I c= P1 & stop I c= P2 & ex k being Element of NAT st Comput (P1,s1,k) = s2 implies Result (P1,s1) = Result (P2,s2) )
set pI = stop I;
assume A1:
I is_closed_on s1,P1
; ( not I is_halting_on s1,P1 or not stop I c= P1 or not stop I c= P2 or for k being Element of NAT holds not Comput (P1,s1,k) = s2 or Result (P1,s1) = Result (P2,s2) )
assume A3:
I is_halting_on s1,P1
; ( not stop I c= P1 or not stop I c= P2 or for k being Element of NAT holds not Comput (P1,s1,k) = s2 or Result (P1,s1) = Result (P2,s2) )
assume
stop I c= P1
; ( not stop I c= P2 or for k being Element of NAT holds not Comput (P1,s1,k) = s2 or Result (P1,s1) = Result (P2,s2) )
then A5:
P1 = P1 +* (stop I)
by FUNCT_4:98;
assume
stop I c= P2
; ( for k being Element of NAT holds not Comput (P1,s1,k) = s2 or Result (P1,s1) = Result (P2,s2) )
then XX:
P2 = P2 +* (stop I)
by FUNCT_4:98;
A2:
s1 = Initialize s1
by MEMSTR_0:44;
then A6:
P1 halts_on s1
by A3, A5, SCMPDS_6:def 3;
then consider n being Element of NAT such that
A7:
CurInstr (P1,(Comput (P1,s1,n))) = halt SCMPDS
by EXTPRO_1:29;
A9:
s2 = Initialize s2
by MEMSTR_0:44;
given k being Element of NAT such that A10:
Comput (P1,s1,k) = s2
; Result (P1,s1) = Result (P2,s2)
set s3 = Comput (P1,s1,k);
set P3 = P1;
A11:
IC in dom (Comput (P1,s1,k))
by MEMSTR_0:2;
IC (Comput (P1,s1,k)) = 0
by MEMSTR_0:def 8, A10;
then
Start-At (0,SCMPDS) c= Comput (P1,s1,k)
by A11, FUNCOP_1:73;
then A14:
Comput (P1,s1,k) = Initialize (Comput (P1,s1,k))
by FUNCT_4:98;
A15:
now let n be
Element of
NAT ;
IC (Comput (P1,(Comput (P1,s1,k)),n)) in dom (stop I)
IC (Comput (P1,(Comput (P1,s1,k)),n)) = IC (Comput (P1,s1,(k + n)))
by EXTPRO_1:4;
hence
IC (Comput (P1,(Comput (P1,s1,k)),n)) in dom (stop I)
by A1, A5, A2, SCMPDS_6:def 2;
verum end;
CurInstr (P1,(Comput (P1,(Comput (P1,s1,k)),n))) =
CurInstr (P1,(Comput (P1,s1,(k + n))))
by EXTPRO_1:4
.=
CurInstr (P1,(Comput (P1,s1,n)))
by A7, EXTPRO_1:5, NAT_1:11
;
then
P1 halts_on Comput (P1,s1,k)
by A7, EXTPRO_1:29;
then A20:
I is_halting_on Comput (P1,s1,k),P1
by A14, A5, SCMPDS_6:def 3;
A21:
DataPart (Comput (P1,s1,k)) = DataPart s2
by A10;
consider k being Element of NAT such that
A22:
CurInstr (P1,(Comput (P1,s1,k))) = halt SCMPDS
by A6, EXTPRO_1:29;
A25:
P1 . (IC (Comput (P1,s1,k))) = halt SCMPDS
by A22, PBOOLE:143;
I is_closed_on Comput (P1,s1,k),P1
by A14, A15, A5, SCMPDS_6:def 2;
then
Result (P1,(Comput (P1,s1,k))) = Result (P2,s2)
by A9, A21, A14, A20, Th29, XX, A5;
hence
Result (P1,s1) = Result (P2,s2)
by A25, EXTPRO_1:8; verum