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10
IshakAltunandDuranTurkoglu
acontradiction.ThusM(xo,x1)1d(fxo,hxo),andthedesiredinequality
isvalidforn11,infact
/
o
d(hxo,hx1)
o(t)dtG(/d(fxo,hxo)
o
o(t)dt)1G(T1)<T1.
Assumethatitistrueforsomen>1.Then
/
o
d(hxn,hxn+1)
o(t)dtG(/M
o
(xn,xn+1)
o(t)dt),
where
M
(xn,xn+1)1max{d(hxn11,hxn),d(hxn,hxn+1)}.
Byassumption,M(xn,xn+1)/10foreachn.IfM(xn,xn+1)1d(hxn,hxn+1),
thenweget
/
o
d(hxn,hxn+1)
o(t)dtG(/M
o
(xn,xn+1)
o(t)dt)
</
o
d(hxn,hxn+1)
o(t)dt,
acontradiction.Therefore,M(xn,xn+1)1d(hxn11,hxn)and
/
o
d(hxn,hxn+1)
o(t)dtG(/M
o
(xn,xn+1)
o(t)dt)
1G(/d(hxn11,hxn)
o
o(t)dt)
G(Tn)1Tn+1.
SinceΣ
convergenttoo.ThereforetheseriesΣ
nl1Tnisconvergent,itfollowsthatΣ
nl1d(hxn,hxn+1)converges.
nl1
o
d(hxn,hxn+1)
o(t)dtis
NowXisd-completeso{hxn}convergestosomezX.Thenw-continuity
offimpliesthatfhxnfz.Sincefandhcommute,andhisw-continuous,
fhxn1hfxn1hhxn11hz.SinceXisHausdorff,hz1fz.Againusing
(7),
/
o
d(hhz,hz)
o(t)dtG(/M
o
(hz,z)
o(t)dt)
and
M
(hz,z)1d(fhz,hz)1d(hfz,hz)1d(hhz,hz),