let S be non empty non void Circuit-like ManySortedSign ; for A being non-empty Circuit of S
for s being State of A
for n being Nat holds Following s,(n + 1) = Following (Following s,n)
let A be non-empty Circuit of S; for s being State of A
for n being Nat holds Following s,(n + 1) = Following (Following s,n)
let s be State of A; for n being Nat holds Following s,(n + 1) = Following (Following s,n)
let n be Nat; Following s,(n + 1) = Following (Following s,n)
consider f being Function of NAT ,(product the Sorts of A) such that
A1:
Following s,n = f . n
and
A2:
f . 0 = s
and
A3:
for n being Nat holds f . (n + 1) = Following (f . n)
by Def8;
thus Following s,(n + 1) =
f . (n + 1)
by A2, A3, Def8
.=
Following (Following s,n)
by A1, A3
; verum