let N be non empty with_non-empty_elements set ; for S being non empty stored-program IC-Ins-separated definite realistic COM-Struct of N
for s being State of S
for iloc, a being Element of NAT holds s . a = (s +* (Start-At iloc,S)) . a
let S be non empty stored-program IC-Ins-separated definite realistic COM-Struct of N; for s being State of S
for iloc, a being Element of NAT holds s . a = (s +* (Start-At iloc,S)) . a
let s be State of S; for iloc, a being Element of NAT holds s . a = (s +* (Start-At iloc,S)) . a
let iloc, a be Element of NAT ; s . a = (s +* (Start-At iloc,S)) . a
X:
a in NAT
;
NAT c= the carrier of S
by Def3;
then
a in the carrier of S
by X;
then
a in dom s
by PARTFUN1:def 4;
then A1:
( dom (Start-At iloc,S) = {(IC S)} & a in (dom s) \/ (dom (Start-At iloc,S)) )
by FUNCOP_1:19, XBOOLE_0:def 3;
a <> IC S
by Def21;
then
not a in {(IC S)}
by TARSKI:def 1;
hence
s . a = (s +* (Start-At iloc,S)) . a
by A1, FUNCT_4:def 1; verum