consider f being Function of [:R^1,R^1:],(TOP-REAL 2) such that
A1:
for x, y being Real holds f . [x,y] = <*x,y*>
by BORSUK_6:20;
take
f
; for x, y being real number holds f . [x,y] = <*x,y*>
let x, y be real number ; f . [x,y] = <*x,y*>
( x is Real & y is Real )
by XREAL_0:def 1;
hence
f . [x,y] = <*x,y*>
by A1; verum