let x0 be Real; for f, f1 being PartFunc of REAL,REAL st f1 is_right_divergent_to+infty_in x0 & ( for r being Real st x0 < r holds
ex g being Real st
( g < r & x0 < g & g in dom f ) ) & ex r being Real st
( 0 < r & (dom f) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f) /\ ].x0,(x0 + r).[ holds
f1 . g <= f . g ) ) holds
f is_right_divergent_to+infty_in x0
let f, f1 be PartFunc of REAL,REAL; ( f1 is_right_divergent_to+infty_in x0 & ( for r being Real st x0 < r holds
ex g being Real st
( g < r & x0 < g & g in dom f ) ) & ex r being Real st
( 0 < r & (dom f) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ & ( for g being Real st g in (dom f) /\ ].x0,(x0 + r).[ holds
f1 . g <= f . g ) ) implies f is_right_divergent_to+infty_in x0 )
assume that
A1:
f1 is_right_divergent_to+infty_in x0
and
A2:
for r being Real st x0 < r holds
ex g being Real st
( g < r & x0 < g & g in dom f )
; ( for r being Real holds
( not 0 < r or not (dom f) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[ or ex g being Real st
( g in (dom f) /\ ].x0,(x0 + r).[ & not f1 . g <= f . g ) ) or f is_right_divergent_to+infty_in x0 )
given r being Real such that A3:
0 < r
and
A4:
(dom f) /\ ].x0,(x0 + r).[ c= (dom f1) /\ ].x0,(x0 + r).[
and
A5:
for g being Real st g in (dom f) /\ ].x0,(x0 + r).[ holds
f1 . g <= f . g
; f is_right_divergent_to+infty_in x0
thus
for r being Real st x0 < r holds
ex g being Real st
( g < r & x0 < g & g in dom f )
by A2; LIMFUNC2:def 5 for seq being Real_Sequence st seq is convergent & lim seq = x0 & rng seq c= (dom f) /\ (right_open_halfline x0) holds
f /* seq is divergent_to+infty
let seq be Real_Sequence; ( seq is convergent & lim seq = x0 & rng seq c= (dom f) /\ (right_open_halfline x0) implies f /* seq is divergent_to+infty )
assume that
A6:
seq is convergent
and
A7:
lim seq = x0
and
A8:
rng seq c= (dom f) /\ (right_open_halfline x0)
; f /* seq is divergent_to+infty
x0 < x0 + r
by A3, Lm1;
then consider k being Nat such that
A9:
for n being Nat st k <= n holds
seq . n < x0 + r
by A6, A7, Th2;
A10:
rng (seq ^\ k) c= rng seq
by VALUED_0:21;
(dom f) /\ (right_open_halfline x0) c= right_open_halfline x0
by XBOOLE_1:17;
then
rng seq c= right_open_halfline x0
by A8, XBOOLE_1:1;
then A11:
rng (seq ^\ k) c= right_open_halfline x0
by A10, XBOOLE_1:1;
then A15:
rng (seq ^\ k) c= ].x0,(x0 + r).[
by TARSKI:def 3;
A16:
(dom f) /\ (right_open_halfline x0) c= dom f
by XBOOLE_1:17;
then A17:
rng seq c= dom f
by A8, XBOOLE_1:1;
then
rng (seq ^\ k) c= dom f
by A10, XBOOLE_1:1;
then A18:
rng (seq ^\ k) c= (dom f) /\ ].x0,(x0 + r).[
by A15, XBOOLE_1:19;
then A19:
rng (seq ^\ k) c= (dom f1) /\ ].x0,(x0 + r).[
by A4, XBOOLE_1:1;
A20:
(dom f1) /\ ].x0,(x0 + r).[ c= dom f1
by XBOOLE_1:17;
then
rng (seq ^\ k) c= dom f1
by A19, XBOOLE_1:1;
then A21:
rng (seq ^\ k) c= (dom f1) /\ (right_open_halfline x0)
by A11, XBOOLE_1:19;
lim (seq ^\ k) = x0
by A6, A7, SEQ_4:20;
then
f1 /* (seq ^\ k) is divergent_to+infty
by A1, A6, A21;
then
f /* (seq ^\ k) is divergent_to+infty
by A22, LIMFUNC1:42;
then
(f /* seq) ^\ k is divergent_to+infty
by A8, A16, VALUED_0:27, XBOOLE_1:1;
hence
f /* seq is divergent_to+infty
by LIMFUNC1:7; verum