let il, k be Nat; NIC ((SCM-goto k),il) = {k}
now for x being object holds
( x in {k} iff x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il } )let x be
object ;
( x in {k} iff x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il } )A1:
now ( x = k implies x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il } )
il in NAT
by ORDINAL1:def 12;
then reconsider il1 =
il as
Element of
Values (IC ) by MEMSTR_0:def 6;
set I =
SCM-goto k;
set t = the
State of
SCM;
set Q = the
Instruction-Sequence of
SCM;
assume A2:
x = k
;
x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il } reconsider n =
il as
Element of
NAT by ORDINAL1:def 12;
reconsider u = the
State of
SCM +* (
(IC ),
il1) as
Element of
product (the_Values_of SCM) by CARD_3:107;
reconsider P = the
Instruction-Sequence of
SCM +* (
il,
(SCM-goto k)) as
Instruction-Sequence of
SCM ;
reconsider ill =
il as
Element of
NAT by ORDINAL1:def 12;
A3:
P /. ill = P . ill
by PBOOLE:143;
IC in dom the
State of
SCM
by MEMSTR_0:2;
then A4:
IC u = n
by FUNCT_7:31;
il in NAT
by ORDINAL1:def 12;
then
il in dom the
Instruction-Sequence of
SCM
by PARTFUN1:def 2;
then A5:
P . n = SCM-goto k
by FUNCT_7:31;
then
IC (Following (P,u)) = k
by A3, A4, AMI_3:7;
hence
x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il }
by A2, A4, A3, A5;
verum end; hence
(
x in {k} iff
x in { (IC (Exec ((SCM-goto k),s))) where s is Element of product (the_Values_of SCM) : IC s = il } )
by A1, TARSKI:def 1;
verum end;
hence
NIC ((SCM-goto k),il) = {k}
by TARSKI:2; verum