let F, G be Function of X,X; ( ( for x being Point of X holds F . x = r * x ) & ( for x being Point of X holds G . x = r * x ) implies F = G )
assume that
A2:
for x being Point of X holds F . x = r * x
and
A3:
for x being Point of X holds G . x = r * x
; F = G
now for x being Point of X holds F . x = G . xlet x be
Point of
X;
F . x = G . xthus F . x =
r * x
by A2
.=
G . x
by A3
;
verum end;
hence
F = G
by FUNCT_2:63; verum