let k, n be Nat; for f being natural-valued Function st n > 1 holds
Coim ((n |^ f),(n |^ k)) = Coim (f,k)
let f be natural-valued Function; ( n > 1 implies Coim ((n |^ f),(n |^ k)) = Coim (f,k) )
assume A1:
n > 1
; Coim ((n |^ f),(n |^ k)) = Coim (f,k)
thus
Coim ((n |^ f),(n |^ k)) c= Coim (f,k)
XBOOLE_0:def 10 Coim (f,k) c= Coim ((n |^ f),(n |^ k))
let x be object ; TARSKI:def 3 ( not x in Coim (f,k) or x in Coim ((n |^ f),(n |^ k)) )
assume
x in Coim (f,k)
; x in Coim ((n |^ f),(n |^ k))
then
x in f " {k}
by RELAT_1:def 17;
then A3:
( x in dom f & f . x in {k} )
by FUNCT_1:def 7;
then A4:
( f . x = k & x in dom (n |^ f) )
by TARSKI:def 1, Def4;
then (n |^ f) . x =
n to_power k
by Def4, A3
.=
n |^ k
;
then
(n |^ f) . x in {(n |^ k)}
by TARSKI:def 1;
then
x in (n |^ f) " {(n |^ k)}
by FUNCT_1:def 7, A4;
hence
x in Coim ((n |^ f),(n |^ k))
by RELAT_1:def 17; verum