let P be non empty strict chain-complete Poset; for g being continuous Function of P,P
for p, p1 being Element of P
for n being Nat st p = (fix_func P) . g & p1 = (iter g,n) . (Bottom P) holds
p1 <= p
let g be continuous Function of P,P; for p, p1 being Element of P
for n being Nat st p = (fix_func P) . g & p1 = (iter g,n) . (Bottom P) holds
p1 <= p
let p, p1 be Element of P; for n being Nat st p = (fix_func P) . g & p1 = (iter g,n) . (Bottom P) holds
p1 <= p
let n be Nat; ( p = (fix_func P) . g & p1 = (iter g,n) . (Bottom P) implies p1 <= p )
set a = Bottom P;
assume A1:
( p = (fix_func P) . g & p1 = (iter g,n) . (Bottom P) )
; p1 <= p
then A2:
p1 in iterSet g,(Bottom P)
;
reconsider g1 = g as Element of (ConPoset P,P) by LemCastFunc02;
reconsider G1 = g1 as continuous Function of P,P ;
p =
least_fix_point G1
by Deffixfunc, A1
.=
sup (iter_min g)
by Thfixpoint01
;
hence
p1 <= p
by Lem201, A2; verum