deffunc H₁( Nat) -> Element of REAL = (Conv_chi_RV (ChiFuncs,$1)) . w;
consider f being Function of NAT,REAL such that
A1: for d being Element of NAT holds f . d = H₁(d) from FUNCT_2:sch 4();
take f ; :: thesis: for n being Nat holds f . n = (Conv_chi_RV (ChiFuncs,n)) . w
let n be Nat; :: thesis: f . n = (Conv_chi_RV (ChiFuncs,n)) . w
n in NAT by ORDINAL1:def 12;
hence f . n = (Conv_chi_RV (ChiFuncs,n)) . w by A1; :: thesis: verum