deffunc H₁( Element of BoundedLinearOperators (X,X), Element of BoundedLinearOperators (X,X)) -> Element of BoundedLinearOperators (X,X) = $1 * $2;
consider F being BinOp of (BoundedLinearOperators (X,X)) such that
A1: for x, y being Element of BoundedLinearOperators (X,X) holds F . (x,y) = H₁(x,y) from BINOP_1:sch 4();
take F ; :: thesis: for f, g being Element of BoundedLinearOperators (X,X) holds F . (f,g) = f * g
let f, g be Element of BoundedLinearOperators (X,X); :: thesis: F . (f,g) = f * g
thus F . (f,g) = f * g by A1; :: thesis: verum