set V = RLMSpace n;
let G1, G2 be strict multMagma ; ( the carrier of G1 = ISOM (RLMSpace n) & ( for f, g being Function st f in ISOM (RLMSpace n) & g in ISOM (RLMSpace n) holds
the multF of G1 . f,g = f * g ) & the carrier of G2 = ISOM (RLMSpace n) & ( for f, g being Function st f in ISOM (RLMSpace n) & g in ISOM (RLMSpace n) holds
the multF of G2 . f,g = f * g ) implies G1 = G2 )
assume that
A7:
the carrier of G1 = ISOM (RLMSpace n)
and
A8:
for f, g being Function st f in ISOM (RLMSpace n) & g in ISOM (RLMSpace n) holds
the multF of G1 . f,g = f * g
and
A9:
the carrier of G2 = ISOM (RLMSpace n)
and
A10:
for f, g being Function st f in ISOM (RLMSpace n) & g in ISOM (RLMSpace n) holds
the multF of G2 . f,g = f * g
; G1 = G2
now let f,
g be
Element of
G1;
the multF of G1 . f,g = the multF of G2 . f,gconsider f1 being
Function of
(RLMSpace n),
(RLMSpace n) such that A11:
f1 = f
and
f1 is
isometric
by A7, Def4;
consider g1 being
Function of
(RLMSpace n),
(RLMSpace n) such that A12:
g1 = g
and
g1 is
isometric
by A7, Def4;
thus the
multF of
G1 . f,
g =
f1 * g1
by A7, A8, A11, A12
.=
the
multF of
G2 . f,
g
by A7, A10, A11, A12
;
verum end;
hence
G1 = G2
by A7, A9, BINOP_1:2; verum