let N be non empty with_non-empty_elements set ; for n being Element of NAT
for S being non empty stored-program IC-Ins-separated definite realistic COM-Struct of N
for I being Program of S holds dom I misses dom (Start-At (n,S))
let n be Element of NAT ; for S being non empty stored-program IC-Ins-separated definite realistic COM-Struct of N
for I being Program of S holds dom I misses dom (Start-At (n,S))
let S be non empty stored-program IC-Ins-separated definite realistic COM-Struct of N; for I being Program of S holds dom I misses dom (Start-At (n,S))
let I be Program of S; dom I misses dom (Start-At (n,S))
A1:
dom (Start-At (n,S)) = {(IC S)}
by FUNCOP_1:19;
assume
(dom I) /\ (dom (Start-At (n,S))) <> {}
; XBOOLE_0:def 7 contradiction
then consider x being set such that
A2:
x in (dom I) /\ (dom (Start-At (n,S)))
by XBOOLE_0:def 1;
( x in dom I & x in dom (Start-At (n,S)) )
by A2, XBOOLE_0:def 4;
then
( dom I c= NAT & IC S in dom I )
by A1, TARSKI:def 1;
then reconsider l = IC S as Element of NAT ;
l = IC S
;
hence
contradiction
by Th3; verum