deffunc H1( Element of Omega) -> Element of REAL = In (((Partial_Sums ((Conv2_RV (ConstFuncs,$1)) (#) (Conv2_RV (ChiFuncs,$1)))) . n),REAL);
consider f being Function of Omega,REAL such that
A1:
for d being Element of Omega holds f . d = H1(d)
from FUNCT_2:sch 4();
take
f
; for w being Element of Omega holds f . w = (Partial_Sums ((Conv2_RV (ConstFuncs,w)) (#) (Conv2_RV (ChiFuncs,w)))) . n
let w be Element of Omega; f . w = (Partial_Sums ((Conv2_RV (ConstFuncs,w)) (#) (Conv2_RV (ChiFuncs,w)))) . n
In (((Partial_Sums ((Conv2_RV (ConstFuncs,w)) (#) (Conv2_RV (ChiFuncs,w)))) . n),REAL) = (Partial_Sums ((Conv2_RV (ConstFuncs,w)) (#) (Conv2_RV (ChiFuncs,w)))) . n
;
hence
f . w = (Partial_Sums ((Conv2_RV (ConstFuncs,w)) (#) (Conv2_RV (ChiFuncs,w)))) . n
by A1; verum