let f1, f2 be BinOp of (CosetSet (M,k)); ( ( for A, B being Element of CosetSet (M,k)
for a, b being PartFunc of X,REAL st a in A & b in B holds
f1 . (A,B) = a.e-eq-class_Lp ((a + b),M,k) ) & ( for A, B being Element of CosetSet (M,k)
for a, b being PartFunc of X,REAL st a in A & b in B holds
f2 . (A,B) = a.e-eq-class_Lp ((a + b),M,k) ) implies f1 = f2 )
assume that
A7:
for A, B being Element of CosetSet (M,k)
for a, b being PartFunc of X,REAL st a in A & b in B holds
f1 . (A,B) = a.e-eq-class_Lp ((a + b),M,k)
and
A8:
for A, B being Element of CosetSet (M,k)
for a, b being PartFunc of X,REAL st a in A & b in B holds
f2 . (A,B) = a.e-eq-class_Lp ((a + b),M,k)
; f1 = f2
now for A, B being Element of CosetSet (M,k) holds f1 . (A,B) = f2 . (A,B)let A,
B be
Element of
CosetSet (
M,
k);
f1 . (A,B) = f2 . (A,B)
A in CosetSet (
M,
k)
;
then consider a1 being
PartFunc of
X,
REAL such that A9:
(
A = a.e-eq-class_Lp (
a1,
M,
k) &
a1 in Lp_Functions (
M,
k) )
;
B in CosetSet (
M,
k)
;
then consider b1 being
PartFunc of
X,
REAL such that A10:
(
B = a.e-eq-class_Lp (
b1,
M,
k) &
b1 in Lp_Functions (
M,
k) )
;
A11:
(
a1 in A &
b1 in B )
by A9, A10, Th38;
then
f1 . (
A,
B)
= a.e-eq-class_Lp (
(a1 + b1),
M,
k)
by A7;
hence
f1 . (
A,
B)
= f2 . (
A,
B)
by A8, A11;
verum end;
hence
f1 = f2
by BINOP_1:2; verum