let N be with_zero set ; for A being non empty with_non-empty_values IC-Ins-separated AMI-Struct over N
for I being Instruction of A st I is halting holds
Out_U_Inp I is empty
let A be non empty with_non-empty_values IC-Ins-separated AMI-Struct over N; for I being Instruction of A st I is halting holds
Out_U_Inp I is empty
let I be Instruction of A; ( I is halting implies Out_U_Inp I is empty )
assume A1:
for s being State of A holds Exec (I,s) = s
; EXTPRO_1:def 3 Out_U_Inp I is empty
assume
not Out_U_Inp I is empty
; contradiction
then consider o being Object of A such that
A2:
o in Out_U_Inp I
;
consider s being State of A, a being Element of Values o such that
A3:
Exec (I,(s +* (o,a))) <> (Exec (I,s)) +* (o,a)
by A2, Def5;
Exec (I,(s +* (o,a))) =
s +* (o,a)
by A1
.=
(Exec (I,s)) +* (o,a)
by A1
;
hence
contradiction
by A3; verum