let r1, r2, x0, x1, x2, x3 be Real; for f1, f2 being Function of REAL,REAL holds [!((r1 (#) f1) + (r2 (#) f2)),x0,x1,x2,x3!] = (r1 * [!f1,x0,x1,x2,x3!]) + (r2 * [!f2,x0,x1,x2,x3!])
let f1, f2 be Function of REAL,REAL; [!((r1 (#) f1) + (r2 (#) f2)),x0,x1,x2,x3!] = (r1 * [!f1,x0,x1,x2,x3!]) + (r2 * [!f2,x0,x1,x2,x3!])
[!((r1 (#) f1) + (r2 (#) f2)),x0,x1,x2,x3!] =
[!(r1 (#) f1),x0,x1,x2,x3!] + [!(r2 (#) f2),x0,x1,x2,x3!]
by Th9
.=
(r1 * [!f1,x0,x1,x2,x3!]) + [!(r2 (#) f2),x0,x1,x2,x3!]
by Th8
;
hence
[!((r1 (#) f1) + (r2 (#) f2)),x0,x1,x2,x3!] = (r1 * [!f1,x0,x1,x2,x3!]) + (r2 * [!f2,x0,x1,x2,x3!])
by Th8; verum