deffunc H₂( Nat) -> Element of the carrier of RNS = (S . $1) - x;
consider S being sequence of RNS such that
A1: for n being Element of NAT holds S . n = H₂(n) from FUNCT_2:sch 4();
take S ; :: thesis: for n being Nat holds S . n = (S . n) - x
let n be Nat; :: thesis: S . n = (S . n) - x
n in NAT by ORDINAL1:def 12;
hence S . n = (S . n) - x by A1; :: thesis: verum