let D be non empty set ; :: thesis: for H being Functional_Sequence of D,REAL
for Y, X being set st Y c= X & Y <> {} & H is_point_conv_on X holds
( H is_point_conv_on Y & (lim H,X) | Y = lim H,Y )
let H be Functional_Sequence of D,REAL ; :: thesis: for Y, X being set st Y c= X & Y <> {} & H is_point_conv_on X holds
( H is_point_conv_on Y & (lim H,X) | Y = lim H,Y )
let Y, X be set ; :: thesis: ( Y c= X & Y <> {} & H is_point_conv_on X implies ( H is_point_conv_on Y & (lim H,X) | Y = lim H,Y ) )
assume A1:
( Y c= X & Y <> {} & H is_point_conv_on X )
; :: thesis: ( H is_point_conv_on Y & (lim H,X) | Y = lim H,Y )
then
X common_on_dom H
by Def12;
then A2:
Y common_on_dom H
by A1, Th24;
consider f being PartFunc of D, REAL such that
A3:
( X = dom f & ( for x being Element of D st x in X holds
for p being Real st p > 0 holds
ex k being Element of NAT st
for n being Element of NAT st n >= k holds
abs (((H . n) . x) - (f . x)) < p ) )
by A1, Def12;
hence A7:
H is_point_conv_on Y
by A2, Def12; :: thesis: (lim H,X) | Y = lim H,Y
dom (lim H,X) = X
by A1, Def14;
then
(dom (lim H,X)) /\ Y = Y
by A1, XBOOLE_1:28;
then
dom ((lim H,X) | Y) = Y
by RELAT_1:90;
then A8:
dom ((lim H,X) | Y) = dom (lim H,Y)
by A7, Def14;
now let x be
Element of
D;
:: thesis: ( x in dom ((lim H,X) | Y) implies ((lim H,X) | Y) . x = (lim H,Y) . x )assume A9:
x in dom ((lim H,X) | Y)
;
:: thesis: ((lim H,X) | Y) . x = (lim H,Y) . xthen
x in (dom (lim H,X)) /\ Y
by RELAT_1:90;
then A10:
(
x in dom (lim H,X) &
x in Y )
by XBOOLE_0:def 4;
then A11:
x in dom (lim H,Y)
by A7, Def14;
thus ((lim H,X) | Y) . x =
(lim H,X) . x
by A9, FUNCT_1:68
.=
lim (H # x)
by A1, A10, Def14
.=
(lim H,Y) . x
by A7, A11, Def14
;
:: thesis: verum end;
hence
(lim H,X) | Y = lim H,Y
by A8, PARTFUN1:34; :: thesis: verum