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 Lm25;
reconsider G1 = g1 as continuous Function of P,P ;
p =
least_fix_point G1
by Def12, A1
.=
sup (iter_min g)
by Th9
;
hence
p1 <= p
by Lm18, A2; verum