let k be natural number ; for N being non empty with_non-empty_elements set
for S being non empty stored-program IC-Ins-separated definite weakly_standard AMI-Struct of N
for l being Element of NAT holds (l + k,S) -' k,S = l
let N be non empty with_non-empty_elements set ; for S being non empty stored-program IC-Ins-separated definite weakly_standard AMI-Struct of N
for l being Element of NAT holds (l + k,S) -' k,S = l
let S be non empty stored-program IC-Ins-separated definite weakly_standard AMI-Struct of N; for l being Element of NAT holds (l + k,S) -' k,S = l
let l be Element of NAT ; (l + k,S) -' k,S = l
thus (l + k,S) -' k,S =
il. S,(((locnum l,S) + k) -' k)
by Def13
.=
il. S,(locnum l,S)
by NAT_D:34
.=
l
by Def13
; verum