let i be Instruction of SCMPDS; for l being Element of NAT st ( for s being State of SCMPDS st IC s = l holds
(Exec (i,s)) . (IC SCMPDS) = succ (IC s) ) holds
NIC (i,l) = {(succ l)}
let l be Element of NAT ; ( ( for s being State of SCMPDS st IC s = l holds
(Exec (i,s)) . (IC SCMPDS) = succ (IC s) ) implies NIC (i,l) = {(succ l)} )
consider t being State of SCMPDS;
reconsider I = i as Instruction of SCMPDS ;
reconsider n = l as Element of NAT ;
assume A1:
for s being State of SCMPDS st IC s = l holds
(Exec (i,s)) . (IC SCMPDS) = succ (IC s)
; NIC (i,l) = {(succ l)}
reconsider il1 = l as Element of ObjectKind (IC SCMPDS) by COMPOS_1:def 6;
((IC SCMPDS),l) --> (il1,I) = ((IC SCMPDS) .--> il1) +* (l .--> I)
by FUNCT_4:def 4;
then reconsider u = t +* (((IC SCMPDS),l) --> (il1,i)) as Element of product the Object-Kind of SCMPDS by PBOOLE:155;
A4:
( IC u = n & u . n = I )
by EXTPRO_1:26;
let x be set ; TARSKI:def 3 ( not x in {(succ l)} or x in NIC (i,l) )
assume
x in {(succ l)}
; x in NIC (i,l)
then A5:
x = succ l
by TARSKI:def 1;
IC (Exec (I,u)) = succ l
by A1, A4;
hence
x in NIC (i,l)
by A5, A4; verum