let x0 be Real; for f1, f2 being PartFunc of REAL,REAL st f1 is_right_convergent_in x0 & f2 is_right_convergent_in x0 & ex r being Real st
( 0 < r & ( ( (dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) or ( (dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) ) ) holds
lim_right (f1,x0) <= lim_right (f2,x0)
let f1, f2 be PartFunc of REAL,REAL; ( f1 is_right_convergent_in x0 & f2 is_right_convergent_in x0 & ex r being Real st
( 0 < r & ( ( (dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) or ( (dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) ) ) implies lim_right (f1,x0) <= lim_right (f2,x0) )
assume that
A1:
f1 is_right_convergent_in x0
and
A2:
f2 is_right_convergent_in x0
; ( for r being Real holds
( not 0 < r or ( not ( (dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) & not ( (dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) ) ) or lim_right (f1,x0) <= lim_right (f2,x0) )
A3:
lim_right (f2,x0) = lim_right (f2,x0)
;
given r being Real such that A4:
0 < r
and
A5:
( ( (dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) or ( (dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) )
; lim_right (f1,x0) <= lim_right (f2,x0)
A6:
lim_right (f1,x0) = lim_right (f1,x0)
;
now per cases
( ( (dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) or ( (dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) ) )
by A5;
suppose A7:
(
(dom f1) /\ ].x0,(x0 + r).[ c= (dom f2) /\ ].x0,(x0 + r).[ & ( for
g being
Real st
g in (dom f1) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) )
;
lim_right (f1,x0) <= lim_right (f2,x0)defpred S1[
Element of
NAT ,
real number ]
means (
x0 < $2 & $2
< x0 + (1 / ($1 + 1)) & $2
in dom f1 );
A8:
now let n be
Element of
NAT ;
ex g being Real st S1[n,g]
x0 < x0 + (1 / (n + 1))
by Lm3;
then consider g being
Real such that A9:
g < x0 + (1 / (n + 1))
and A10:
x0 < g
and A11:
g in dom f1
by A1, Def4;
take g =
g;
S1[n,g]thus
S1[
n,
g]
by A9, A10, A11;
verum end; consider s being
Real_Sequence such that A12:
for
n being
Element of
NAT holds
S1[
n,
s . n]
from FUNCT_2:sch 3(A8);
A13:
lim s = x0
by A12, Th6;
A14:
rng s c= (dom f1) /\ (right_open_halfline x0)
by A12, Th6;
A15:
].x0,(x0 + r).[ c= right_open_halfline x0
by XXREAL_1:247;
A16:
s is
convergent
by A12, Th6;
x0 < x0 + r
by A4, Lm1;
then consider k being
Element of
NAT such that A17:
for
n being
Element of
NAT st
k <= n holds
s . n < x0 + r
by A16, A13, Th2;
A18:
lim (s ^\ k) = x0
by A16, A13, SEQ_4:33;
then A22:
rng (s ^\ k) c= (dom f1) /\ ].x0,(x0 + r).[
by TARSKI:def 3;
then A23:
rng (s ^\ k) c= (dom f2) /\ ].x0,(x0 + r).[
by A7, XBOOLE_1:1;
(dom f2) /\ ].x0,(x0 + r).[ c= ].x0,(x0 + r).[
by XBOOLE_1:17;
then
rng (s ^\ k) c= ].x0,(x0 + r).[
by A23, XBOOLE_1:1;
then A24:
rng (s ^\ k) c= right_open_halfline x0
by A15, XBOOLE_1:1;
A25:
(dom f2) /\ ].x0,(x0 + r).[ c= dom f2
by XBOOLE_1:17;
then
rng (s ^\ k) c= dom f2
by A23, XBOOLE_1:1;
then A26:
rng (s ^\ k) c= (dom f2) /\ (right_open_halfline x0)
by A24, XBOOLE_1:19;
then A27:
lim (f2 /* (s ^\ k)) = lim_right (
f2,
x0)
by A2, A16, A18, Def8;
rng (s ^\ k) c= rng s
by VALUED_0:21;
then A28:
rng (s ^\ k) c= (dom f1) /\ (right_open_halfline x0)
by A14, XBOOLE_1:1;
then A29:
lim (f1 /* (s ^\ k)) = lim_right (
f1,
x0)
by A1, A16, A18, Def8;
A30:
(dom f1) /\ ].x0,(x0 + r).[ c= dom f1
by XBOOLE_1:17;
A32:
f2 /* (s ^\ k) is
convergent
by A2, A3, A16, A18, A26, Def8;
f1 /* (s ^\ k) is
convergent
by A1, A6, A16, A18, A28, Def8;
hence
lim_right (
f1,
x0)
<= lim_right (
f2,
x0)
by A29, A32, A27, A31, SEQ_2:32;
verum end; suppose A33:
(
(dom f2) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for
g being
Real st
g in (dom f2) /\ ].x0,(x0 + r).[ holds
f1 . g <= f2 . g ) )
;
lim_right (f1,x0) <= lim_right (f2,x0)defpred S1[
Element of
NAT ,
real number ]
means (
x0 < $2 & $2
< x0 + (1 / ($1 + 1)) & $2
in dom f2 );
consider s being
Real_Sequence such that A38:
for
n being
Element of
NAT holds
S1[
n,
s . n]
from FUNCT_2:sch 3(A34);
A39:
lim s = x0
by A38, Th6;
A40:
rng s c= (dom f2) /\ (right_open_halfline x0)
by A38, Th6;
A41:
].x0,(x0 + r).[ c= right_open_halfline x0
by XXREAL_1:247;
A42:
s is
convergent
by A38, Th6;
x0 < x0 + r
by A4, Lm1;
then consider k being
Element of
NAT such that A43:
for
n being
Element of
NAT st
k <= n holds
s . n < x0 + r
by A42, A39, Th2;
A44:
lim (s ^\ k) = x0
by A42, A39, SEQ_4:33;
then A49:
rng (s ^\ k) c= (dom f2) /\ ].x0,(x0 + r).[
by TARSKI:def 3;
then A50:
rng (s ^\ k) c= (dom f1) /\ ].x0,(x0 + r).[
by A33, XBOOLE_1:1;
(dom f1) /\ ].x0,(x0 + r).[ c= ].x0,(x0 + r).[
by XBOOLE_1:17;
then
rng (s ^\ k) c= ].x0,(x0 + r).[
by A50, XBOOLE_1:1;
then A51:
rng (s ^\ k) c= right_open_halfline x0
by A41, XBOOLE_1:1;
A52:
(dom f1) /\ ].x0,(x0 + r).[ c= dom f1
by XBOOLE_1:17;
then
rng (s ^\ k) c= dom f1
by A50, XBOOLE_1:1;
then A53:
rng (s ^\ k) c= (dom f1) /\ (right_open_halfline x0)
by A51, XBOOLE_1:19;
then A54:
lim (f1 /* (s ^\ k)) = lim_right (
f1,
x0)
by A1, A42, A44, Def8;
rng (s ^\ k) c= rng s
by VALUED_0:21;
then A55:
rng (s ^\ k) c= (dom f2) /\ (right_open_halfline x0)
by A40, XBOOLE_1:1;
then A56:
lim (f2 /* (s ^\ k)) = lim_right (
f2,
x0)
by A2, A42, A44, Def8;
A57:
(dom f2) /\ ].x0,(x0 + r).[ c= dom f2
by XBOOLE_1:17;
A59:
f1 /* (s ^\ k) is
convergent
by A1, A6, A42, A44, A53, Def8;
f2 /* (s ^\ k) is
convergent
by A2, A3, A42, A44, A55, Def8;
hence
lim_right (
f1,
x0)
<= lim_right (
f2,
x0)
by A56, A59, A54, A58, SEQ_2:32;
verum end; end; end;
hence
lim_right (f1,x0) <= lim_right (f2,x0)
; verum