let A be non empty closed_interval Subset of REAL; for f being Function of A,REAL
for T being DivSequence of A
for S being middle_volume_Sequence of f,T
for i being Element of NAT st f | A is bounded_above holds
(middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
let f be Function of A,REAL; for T being DivSequence of A
for S being middle_volume_Sequence of f,T
for i being Element of NAT st f | A is bounded_above holds
(middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
let T be DivSequence of A; for S being middle_volume_Sequence of f,T
for i being Element of NAT st f | A is bounded_above holds
(middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
let S be middle_volume_Sequence of f,T; for i being Element of NAT st f | A is bounded_above holds
(middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
let i be Element of NAT ; ( f | A is bounded_above implies (middle_sum (f,S)) . i <= (upper_sum (f,T)) . i )
assume A1:
f | A is bounded_above
; (middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
( (middle_sum (f,S)) . i = middle_sum (f,(S . i)) & (upper_sum (f,T)) . i = upper_sum (f,(T . i)) )
by Def4, INTEGRA2:def 2;
hence
(middle_sum (f,S)) . i <= (upper_sum (f,T)) . i
by A1, Th2; verum