let I be Instruction of S; ( I is halting implies I is IC-good )
assume A1:
I is halting
; I is IC-good
let k be natural number ; AMISTD_2:def 18 for s1 being State of S holds (IC (Exec I,s1)) + k = IC (Exec (IncAddr I,k),(IncrIC s1,k))
let s1 be State of S; (IC (Exec I,s1)) + k = IC (Exec (IncAddr I,k),(IncrIC s1,k))
set s2 = IncrIC s1,k;
dom ((IC S) .--> ((IC s1) + k)) = {(IC S)}
by FUNCOP_1:19;
then A3:
IC S in dom ((IC S) .--> ((IC s1) + k))
by TARSKI:def 1;
thus (IC (Exec I,s1)) + k =
(IC s1) + k
by A1, AMI_1:def 8
.=
((IC S) .--> ((IC s1) + k)) . (IC S)
by FUNCOP_1:87
.=
IC (IncrIC s1,k)
by A3, FUNCT_4:14
.=
IC (Exec I,(IncrIC s1,k))
by A1, AMI_1:def 8
.=
IC (Exec (IncAddr I,k),(IncrIC s1,k))
by A1, Th29
; verum