let f be heterogeneous non empty real-valued positive FinSequence; for i, j being Nat st i in dom f & j in dom f & i <> j & j in MeanMore f & i in MeanLess f holds
ex g being non empty real-valued positive FinSequence st
( g = Replace (f,i,j,(Mean f),(((f . i) + (f . j)) - (Mean f))) & GMean f < GMean g )
let i, j be Nat; ( i in dom f & j in dom f & i <> j & j in MeanMore f & i in MeanLess f implies ex g being non empty real-valued positive FinSequence st
( g = Replace (f,i,j,(Mean f),(((f . i) + (f . j)) - (Mean f))) & GMean f < GMean g ) )
assume A1:
( i in dom f & j in dom f & i <> j & j in MeanMore f & i in MeanLess f )
; ex g being non empty real-valued positive FinSequence st
( g = Replace (f,i,j,(Mean f),(((f . i) + (f . j)) - (Mean f))) & GMean f < GMean g )
reconsider a = Mean f as positive Real ;
b1:
( f . i > 0 & f . j > 0 )
by A1, PosDef;
h1:
Mean f < f . j
by A1, BlaBla2;
then h2:
(Mean f) - (Mean f) < (f . j) - (Mean f)
by XREAL_1:14;
f . i > 0
by A1, PosDef;
then
((f . j) - (Mean f)) + (f . i) > 0
by h2;
then reconsider b = ((f . i) + (f . j)) - (Mean f) as positive Real ;
set g = Replace (f,i,j,a,b);
jj:
dom f = dom (Replace (f,i,j,a,b))
by DinoDom;
reconsider g = Replace (f,i,j,a,b) as non empty real-valued positive FinSequence by ReplacePositive2, A1, h1;
take
g
; ( g = Replace (f,i,j,(Mean f),(((f . i) + (f . j)) - (Mean f))) & GMean f < GMean g )
( f . j > (Mean f) + 0 & Mean f > (f . i) + 0 )
by A1, BlaBla2;
then
( (f . j) - (Mean f) > 0 & (Mean f) - (f . i) > 0 )
by XREAL_1:20;
then
((f . j) - (Mean f)) * ((Mean f) - (f . i)) > 0
;
then k2:
((a * b) - ((f . i) * (f . j))) + ((f . i) * (f . j)) > 0 + ((f . i) * (f . j))
by XREAL_1:8;
(a * b) / ((f . i) * (f . j)) > 1
by k2, XREAL_1:187, b1;
then
(Product f) * ((a * b) / ((f . i) * (f . j))) > (Product f) * 1
by XREAL_1:68;
then
((Product f) * (a * b)) / ((f . i) * (f . j)) > Product f
by XCMPLX_1:74;
then
(((Product f) * a) * b) / ((f . i) * (f . j)) > Product f
;
then
Product g > Product f
by A1, ProdReplace;
hence
( g = Replace (f,i,j,(Mean f),(((f . i) + (f . j)) - (Mean f))) & GMean f < GMean g )
by ProdGMean, jj, FINSEQ_3:29; verum