let a, b, c be Real; ( a > 1 & c > b implies a #R c > a #R b )
assume that
A1:
a > 1
and
A2:
c > b
; a #R c > a #R b
consider p being Rational such that
A3:
b < p
and
A4:
p < c
by A2, RAT_1:7;
consider q being Rational such that
A5:
b < q
and
A6:
q < p
by A3, RAT_1:7;
consider s2 being Rational_Sequence such that
A7:
s2 is convergent
and
A8:
b = lim s2
and
A9:
for n being Nat holds s2 . n <= b
by Th67;
A10:
a #Q q < a #Q p
by A1, A6, Th64;
then A11:
lim (a #Q s2) <= a #Q q
by A1, A7, Th2, Th69;
a #Q s2 is convergent
by A1, A7, Th69;
then
a #R b <= a #Q q
by A1, A7, A8, A11, Def6;
then A12:
a #R b < a #Q p
by A10, XXREAL_0:2;
consider s1 being Rational_Sequence such that
A13:
s1 is convergent
and
A14:
c = lim s1
and
A15:
for n being Nat holds s1 . n >= c
by Th68;
then A16:
lim (a #Q s1) >= a #Q p
by A1, A13, Th1, Th69;
a #Q s1 is convergent
by A1, A13, Th69;
then
a #R c >= a #Q p
by A1, A13, A14, A16, Def6;
hence
a #R c > a #R b
by A12, XXREAL_0:2; verum