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doi:10.1155/2010/795145

Research Article

Nonlinear Delay Discrete Inequalities and Their Applications to Volterra Type Difference Equations

Yu Wu,

1

Xiaopei Li,

2

and Shengfu Deng

3

1Yibin University, Yibin, Sichuan 644007, China

2Department of Mathematics, Zhanjiang Normal University, Zhanjiang, Guangdong 524048, China

3Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088, China

Correspondence should be addressed to Shengfu Deng,sf [email protected] Received 7 September 2009; Accepted 14 January 2010

Academic Editor: Abdelkader Boucherif

Copyrightq2010 Yu Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Delay discrete inequalities with more than one nonlinear term are discussed, which generalize some known results and can be used in the analysis of various problems in the theory of certain classes of discrete equations. Application examples to show boundedness and uniqueness of solutions of a Volterra type difference equation are also given.

1. Introduction

Gronwall-Bellman inequalities and their various linear and nonlinear generalizations play very important roles in the discussion of existence, uniqueness, continuation, boundedness, and stability properties of solutions of differential equations and difference equations. The literature on such inequalities and their applications is vast. For example, see 1–12 for continuous cases, and 13–20 for discrete cases. In particular, the book 21 written by Pachpatte considered three types of discrete inequalities:

unan n−1

s0

fswus, u2n≤an 2

n−1 s0

fsus,

u2n≤an n−1

s0

fswus.

1.1

(2)

In this paper, we consider a delay discrete inequality

unan m

i1 bin−1 sbi0

fin, swius, nN0 1.2

which has m nonlinear terms where N0 {0,1,2, . . .}. We will show that many discrete inequalities like1.1can be reduced to this form. Our main result can be applied to analyze properties of solutions of discrete equations. We also give examples to show boundedness and uniqueness of solutions of a Volterra type difference equation.

2. Main Results

Assume that

C1anis nonnegative fornN0anda0>0;

C2bin i1, . . . , mare nondecreasing fornN0, the range of eachbibelongs toN0, andbin≤n;

C3allfin, j i1, . . . , mare nonnegative forn, jN0;

C4allwi i1, . . . , mare continuous and nondecreasing functions on0,∞and are positive on0,∞. They satisfy the relationshipw1w2∝ · · · ∝wmwherewiwi1

means thatwi1/wiis nondecreasing on0,∞ see10.

LetWiu u

uidz/wizforuui whereui > 0 is a given constant. Then,Wiis strictly increasing so its inverseWi−1is well defined, continuous, and increasing in its corresponding domain. Definebi−1 −1,Δun un1−unandΔ2rn, j rn, j1−rn, j.

Theorem 2.1. Suppose that (C1)–(C4) hold andunis a nonnegative function fornN0satisfying 1.2. Then

unWm−1

Wma0 bmn−1

sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

, nN1, 2.1

wherean max0≤τ≤n,τ∈N0,fin, j max0≤τ≤n,τ∈N0fiτ, j,rmn, jis determined recursively by

r1

n, j a

j , ri1

n, j

Wir1n,0

bij−1 sbi0

fin, s j−1

s0

Δ2rin, s φi

Wi−1−1ri0, s, i1, . . . , m−1, 2.2

φiu wiu/wi−1u,φ1u w1u,W0 I(Identity), andN1 is the largest positive integer such that

Wia0 biN1−1

sbi0

fiN1, s N1−1

s0

Δ2riN1, s φi

Wi−1−1ri0, s ≤

ui

dz

wiz, i1, . . . , m. 2.3

(3)

Remark 2.2. 1 N1 is defined by 2.3 and N1 ∞ when all wi i 1, . . . , m satisfy

uidz/wiz ∞. Different choices ofuiinWido not affect our resultssee2.

2Ifbin nfori1, . . . , m, then2.1gives the estimate of the following inequality:

unan m

i1

n−1 s0

fin, swius, nN0 2.4

by replacingbmn−1,bm0,bij−1,bi0, andbiN1−1withn−1, 0,j−1, 0 andN1−1, respectively. Especially, ifb1n nandf1n, s fs, then1.2form1 becomes the first inequality of1.1. Equation2.1shows the same estimate given byb1of Theorem 4.2.3 in the book21.

Lemma 2.3. Δ2rin, j is nonnegative and nondecreasing in n, and rin, j is nonnegative and nondecreasing innandjfori1, . . . , m.

Proof. By the definitions ofan andfin, j, it is easy to check that they are nonnegative and nondecreasing inn, andananandfin, j≥fin, jfor each fixedjwherei1, . . . , m.

a0>0 inC1implies thatan >0 for allnN1. Clearly,

Δ2r1

n1, j

−Δ2r1

n, j 0, Δ2r2

n1, j

−Δ2r2

n, j f1

n1, b1

j

f1

n, b1

j Δ2r1

n1, j

−Δ2r1

n, j w1

r1

0, j ≥0, 2.5

wherer10, j aj >0 is used, which yields thatΔ2r1n, jandΔ2r2n, jare nondecreasing inn. Assume thatΔ2rln, jis nondecreasing inn. Then

Δ2rl1

n1, j

−Δ2rl1 n, j

fl

n1, bl

j

fl

n, bl

j Δ2rl

n1, j

−Δ2rl

n, j φl

Wl−1−1 rl

0, j ≥0, 2.6

which implies thatΔ2rl1n, jis nondecreasing inn. By induction,Δ2rin, j i 1, . . . , m are nondecreasing inn. Similarly, we can prove that they are nonnegative by induction again.

Thenrin, j i1, . . . , mare nonnegative and nondecreasing innandj.

Proof ofTheorem 2.1. Take any arbitrary positive integernN1 and consider the auxiliary inequality

unr1n, n m

i1 bin−1 sbi0

fin, swius, nn. 2.7

(4)

Claim thatunin2.7satisfies

unWm−1

Wmr1n,0

bmn−1 sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

⎦ 2.8

forn≤ {n, N2}whereN2is the largest positive integer such that

Wir1n,0

biN2−1 sbi0

fin, s N2−1

s0

Δ2rin, s φi

Wi−1−1ri0, s ≤

ui

dz

wiz, 2.9

i1, . . . , m.

Before we prove2.8, notice thatN1N2. In fact,rin, n,Δ2rin, n, andfin, nare nondecreasing innbyLemma 2.3. Thus,N2satisfying2.9gets smaller asnis chosen larger.

In particular,N2satisfies the same2.3asN1fornN1ifr1n,0 a0 is applied.

We divide the proof of2.8into two steps by using induction.

Step 1m1. Letzn b1n−1

sb10f1n, sw 1usfornnandz0 0. It is clear thatzn is nonnegative and nondecreasing. Observe that2.7is equivalent tounr1n, n zn fornnand by assumptionsC2andC4andLemma 2.3,

Δzn f1n, b1nw1ub1n≤f1n, b1nw1r1n, b1n zb1n

f1n, b1nw1r1n, n zn. 2.10

Sincew1is nondecreasing andr1n, n an >0, we have Δzn Δ2r1n, n

w1r1n, n znf1n, b1n Δ2r1n, n w1r1n, n zn

f1n, b1n Δ2r1n, n w1r10, n.

2.11

Then

zn1r1n,n1

znr1n,n

w1τ ≤

zn1r1n,n1

znr1n,n

w1zn r1n, n

≤ Δzn Δ2r1n, n w1zn r1n, n

f1n, b1n Δ2r1n, n w1r10, n,

2.12

(5)

and so

znr1n,n

z0r1n,0

w1τ n−1

s0

zs1r1n,s1

zsr1n,s

w1τ

n−1

s0

f1n, b 1s n−1

s0

Δ2r1n, s w1r10, s

b1n−1

sb10

f1n, s n−1

s0

Δ2r1n, s w1r10, s.

2.13

The definition ofW1inTheorem 2.1andz0 0 show

W1zn r1n, nW1r1n,0 b1n−1

sb10

f1n, s n−1

s0

Δ2r1n, s

w1r10, s, nn. 2.14

Equation2.9shows that the right side of2.14is in the domain ofW1−1for allnn. Thus the monotonicity ofW1−1implies

unzn r1n, nW1−1

W1r1n, 0

b1n−1 sb10

f1n, s n−1

s0

Δ2r1n, s w1r10, s

⎦ 2.15

fornn; that is, 2.8is true form1.

Step 2mk1. Assume that2.8is true formk. Consider

unr1n, n k1

i1 bin−1 sbi0

fin, swius, nn. 2.16

Let zn k1

i1 bin−1

sbi0fin, swius and z0 0. Then zn is nonnegative and nondecreasing and satisfiesunr1n, n znfornn. Moreover, we have

Δzn k1

i1

fin, b inwiubin≤k1

i1

fin, binwir1n, b in zbin. 2.17

(6)

Since wi and r1 are nondecreasing in their arguments and r1n, n > 0, we have by the assumptionbin≤n

Δzn Δ2r1n, n w1zn r1n,n ≤

k1

i1 fin, b inwizbin r1n, bin

w1zn r1n, n Δ2r1n, n w1r1n, n

f1n, b 1n k1

i2

fin, binwizbin r1n, b in

w1zbin r1n, b in Δ2r1n, n w1r10, n

f1n, b 1n k

i1

fi1n, b i1nφi1zbi1n r1n, bi1n

Δ2r1n, n w1r10, n

2.18

fornnwhereφi1u wi1u/w1ufori1, . . . , k, which gives zn1r1n,n1

znr1n,n

w1τ ≤

zn1r1n,n1

znr1n,n

w1zn r1n, n

≤ Δzn Δ2r1n, n w1r1n, n zn

f1n, b1n Δ2r1n, n w1r10, n k

i1

fi1n, bi1nφi1zbi1n r1n, bi1n.

2.19

Therefore, znr1n,n

z0r1n,0

w1τ ≤b1n−1

sb10

f1n, s n−1

s0

Δ2r1n, s w1r10, s

k

i1

n−1 s0

fi1n, bi1sφi1zbi1s r1n, bi1s,

2.20

that is,

W1zn r1n, nW1r1n,0 b1n−1

sb10

f1n, s n−1

s0

Δ2r1n, s w1r10, s

k

i1 bi1n−1 sbi10

fi1n, sφi1zs r1n, s,

2.21

(7)

or equivalently

ξnc1n, n k

i1 bi1n−1 sbi10

fi1n, sφi1

W1−1ξs

, nn, 2.22

the same as2.7formkwhereξn W1zn r1n, nand

c1n, n W1r1n,0

b1n−1 sb10

f1n, s n−1

s0

Δ2r1n, s

w1r10, s. 2.23

From the assumption C4, each φi1W1−1, i 1, . . . , k, is continuous and nondecreasing on 0,∞ and is positive on0,∞ sinceW1−1 is continuous and nondecreasing on0,∞.

Moreover,φ2W1−1φ3W1−1∝ · · · ∝φk1W1−1. By the inductive assumption, we have

ξn≤Φ−1k1

⎣Φk1c1n, 0 bk1n−1

sbk10

fk1n, s n−1

s0

Δ2ckn, s ψk1

Φ−1k ck0, s

⎦ 2.24

forn≤ min{n, N3}whereΦi1u u

ui1dz/φi1W1−1z,u > 0,Φ1 I Identity,ui1 W1ui1−1i1 is the inverse ofΦi1,ψi1u φi1W1−1u/φiW1−1u wi1W1−1u/

wiW1−1u, i1, . . . , k,

ci1n, n Φi1c1n, 0 bi1n−1

sbi10

fi1n, s n−1

s0

Δ2cin, s ψi1

Φ−1i ci0, s, 2.25

i 1, . . . , k−1,andN3is the largest positive integer such that

Φi1c1n,0 bi1N3−1

sbi10

fi1n, s N3−1

s0

Δ2cin, s ψi1

Φ−1i ci0, s

W1

ui1

dz φi1

W1−1z, i1, . . . , k.

2.26

(8)

Note that

Φiu u

ui

dz φi

W1−1z u

W1ui

w1

W1−1z dz wi

W1−1z

W−1

1 u

ui

dz

wiz WiW1−1u, i2, . . . , k1,

ψi1

Φ−1i u

wi1 W1−1

Φ−1i u wi

W1−1

Φ−1i u wi1 W1−1

W1

Wi−1u wi

W1−1 W1

Wi−1u wi1

Wi−1u wi

Wi−1u φi1

Wi−1u

, i1, . . . , k1.

2.27

Thus, we have from2.24that

unr1n, n zn W1−1ξn

Wk1−1

Wk1

W1−1c1n,0

bk1n−1 sbk10

fk1n, s n−1

s0

Δ2ckn, s φk1

Wk−1ck0, s

Wk1−1

Wk1r1n,0

bk1n−1 sbk10

fk1n, s n−1

s0

Δ2ckn, s φk1

Wk−1ck0, s

2.28

forn≤min{n, N 3}since c1n,0 W1r1n,0.

In the following, we prove thatcin, n ri1n, nby induction again.

It is clear thatc1n, n r2n, nfori1. Suppose thatcln, n rl1n, n foril. We have

cl1n, n Φl1c1n, 0 bl1n−1

sbl10

fl1n, s n−1

s0

Δ2cln, s ψl1

Φ−1l cl0, s Wl1r1n,0 bl1n−1

sbl10

fl1n, s n−1

s0

Δ2rl1n, s φl1

Wl−1rl10, s rl2n, n,

2.29

wherec1n,0 W1r1n,0is applied. It implies that it is true foril1. Thus,cin, n ri1n, nfori1, . . . , k.

(9)

Equation2.26becomes

Wi1r1n,0

bi1N3−1 sbi10

fi1n, s N3−1

s0

Δ2ri1n, s φi1

Wi−1ri10, s

W1

ui1

dz φi1

W1−1z W1

ui1

w1

W1−1z wi1

W1−1zdz

ui1

dz wi1z

2.30

fori1, . . . , k. It implies thatN2N3. Thus,2.28becomes

unWk1−1

Wk1r1n,0 bk1n−1

sbk10

fk1n, s n−1

s0

Δ2rk1n, s φk1

Wk−1rk10, s

⎦ 2.31

fornn. It shows that 2.8is true formk1. Thus, the claim is proved.

Now we prove2.1. Replacingnbynin2.8, we have

unWm−1

Wmr1n,0 bmn−1

sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

. 2.32

Since2.8is true for anynN1, we replacenbynand get

unWm−1

Wmr1n,0 bmn−1

sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

. 2.33

This is exactly2.1sincer1n,0 a0. This proves Theorem 2.1.

Remark 2.4. Ifan 0 for allnN0, thena0 0. Letr1,u1n, j:r1n, j u1whereu1>0 is given inW1u u

u1dz/w1z. Using the same arguments as in2.11wherer1n, jis replaced with the positiver1,u1n, j, we haveΔ2r1,u1n, s 0 and2.14becomes

W1zn r1,u1n, nW1r1,u1n,0 b1n−1

sb10

f1n, s

W1u1

b1n−1 sb10

f1n, s b1n−1

sb10

f1n, s,

2.34

that is,

unzn r1,u1n, n zn u1

W1−1

b1n−1

sb10

f1n, s

, nn, 2.35

(10)

which is the same as2.15with a complementary definition thatW10 0. From 1 of Remark 2.2, the estimate of2.35is independent ofu1. Then we similarly obtain2.1and all riare defined by the same formula2.2where we defineWi0 0 fori1, . . . , m.

3. Some Corollaries

In this section, we applyTheorem 2.1and obtain some corollaries.

Assume that ϕCR,R is a strictly increasing function with ϕ∞ ∞ where R 0,∞. Consider the inequality

ϕunan m

i1 bin−1 sbi0

fin, swius, nN0. 3.1

Corollary 3.1. Suppose thatC1)–(C4) hold. Ifunin3.1is nonnegative fornN0, then

unϕ−1

⎢⎣Wm−1

⎜⎝Wma0 bmn−1

sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

⎟⎠

⎥⎦ 3.2

for nN1 where Wiu u

uidz/wiϕ−1z, Wi−1 is the inverse of Wi,W0 IIdentity, φiu wiϕ−1u/wi−1ϕ−1u,φ1u w1ϕ−1u, and other related functions are defined as inTheorem 2.1by replacingwiuwithwiϕ−1u.

Proof. Letξn ϕun. Then3.1becomes

ξnan m

i1 bin−1

sbi0

fin, swi

ϕ−1ξs

, nN0. 3.3

Note thatwiϕ−1usatisfyC4fori1, . . . , m. UsingTheorem 2.1, we obtain the estimate aboutξnby replacingwiuwithwiϕ−1u. Then use the fact thatun ϕ−1ξnand we getCorollary 3.1.

Ifϕu upwherep >0, then3.1reads

upn≤an m

i1 bin−1

sbi0

fin, swius, nN0. 3.4

Directly usingCorollary 3.1, we have the following result.

Corollary 3.2. Suppose thatC1)–(C4) hold. Ifunin3.4is nonnegative fornN0, then

un

⎢⎣Wm−1

⎜⎝Wma0 bmn−1

sbm0

fmn, s n−1

s0

Δ2rmn, s φm

Wm−1−1 rm0, s

⎟⎠

⎥⎦

1/p

3.5

(11)

fornN1 whereWiu u

uidz/wiz1/p,Wiis the inverse ofWi,W0 IIdentity,φiu wiu1/p/wi−1u1/p,φ1u w1u1/p, and other related functions are defined as inTheorem 2.1 by replacingwiuwithwiu1/p.

Ifm1,p2,b1n n,3.4becomes the second inequality of1.1withf1n, s 2fsandw1u u, and the third inequality of1.1withf1n, s fsandw1u wu, which are discussed in the book21. Equation3.5yields the same estimates of Theorem 4.2.4 in the book21.

4. Applications to Volterra Type Difference Equations

In this section, we applyTheorem 2.1to study boundedness and uniqueness of solutions of a nonlinear delay difference equation of the form

yn βn b1n−1

sb10

F

n, s, ys

b2n−1

sb20

H

n, s, ys

, nN0, 4.1

where y : N0R is an unknown function,β maps from N0 to R,F and H map from N0×N0×R to R, andbisatisfies the assumptionC2fori1,2.

Theorem 4.1. Suppose thatβ0/0 and the functionsFandHin4.1satisfy the conditions

F

n, s, yf1n, sy, H

n, s, yf2n, sy,

4.2

wheref1, f2:N0×N0 → 0,∞. Ifynis a solution of4.1onN0, then

yna0 exp

⎢⎣

b2n−1 sb20

f2n, s n−1

s0

f1n, b1s

Δas/

as

hs

⎥⎦, 4.3

where

as max

0≤τ≤s,τ∈N0

βτ, f1n, s max

0≤τ≤n,τ∈N0

f1τ, s, f2n, s max

0≤τ≤n,τ∈N0

f2τ, s,

hn

a0 1

2

b1n−1 sb10

f10, s 1 2

n−1

s0

Δas as .

4.4

(12)

Proof. Using4.1and4.2, the solutionynsatisfies

unan b1n−1

sb10

f1n, sw1us b2n−1

sb20

f2n, sw2us, nN0, 4.5

where

un yn, an βn, w1u √

u, w2u u. 4.6

Clearly,an >0 for allnN0sinceβ0/0. For positive constantsu1, u2, we have

W1u u

u1

dz

w1z 2√ u−√

u1

, W1−1u u 2 √

u1

2

, W2u

u

u2

dz

w2z ln u

u2, W2−1u u2expu, r1

n, j a

j

>0, r1n,0 a0,

r2

n, j 2

a0 −√ u1

b1j−1 sb10

f1n, s j−1

s0

Δas as , Δ2r2

n, j f1

n, b1

j Δa

j a

j, φ2u w2u w1u √

u.

4.7

It is obvious thatw1andw2satisfyC4. ApplyingTheorem 2.1gives

una0 exp

⎢⎣

b2n−1 sb20

f2n, s n−1

s0

f1n, b1s

Δas/

as

hs

⎥⎦ 4.8

which implies4.3.

Theorem 4.2. Suppose thatβ0/0 and the functionsFandHin4.1satisfy the conditions F

n, s, y1

F

n, s, y2f1n, sy1y2, H

n, s, y1

H

n, s, y2f2n, sy1y2,

4.9

wheref1, f2:N0×N0 → 0,∞. Then4.1has at most one solution onN0. Proof. Lety1nandy2nbe two solutions of4.1onN0. From4.9, we have

|un| ≤b1n−1

sb10

f1n, sw1us b2n−1

sb20

f2n, sw2us, nN0, 4.10

(13)

whereun |y1n−y2n|,an 0,w1u √

uandw2u u. ApplingTheorem 2.1, Remark 2.4, and the notationWi0 0 fori1,2, we obtain thatun 0 which implies that the solution is unique.

Acknowledgments

This paper was supported by Guangdong Provincial natural science Foundation07301595.

The authors would like to thank Professor Boling Guo for his great help.

References

1 R. P. Agarwal, “On an integral inequality innindependent variables,” Journal of Mathematical Analysis and Applications, vol. 85, no. 1, pp. 192–196, 1982.

2 R. P. Agarwal, S. Deng, and W. Zhang, “Generalization of a retarded Gronwall-like inequality and its applications,” Applied Mathematics and Computation, vol. 165, no. 3, pp. 599–612, 2005.

3 I. Bihari, “A generalization of a lemma of Bellman and its application to uniqueness problems of differential equations,” Acta Mathematica Academiae Scientiarum Hungaricae, vol. 7, pp. 81–94, 1956.

4 W.-S. Cheung, “Some new nonlinear inequalities and applications to boundary value problems,”

Nonlinear Analysis: Theory, Methods & Applications, vol. 64, no. 9, pp. 2112–2128, 2006.

5 S. K. Choi, S. Deng, N. J. Koo, and W. Zhang, “Nonlinear integral inequalities of Bihari-type without classH,” Mathematical Inequalities & Applications, vol. 8, no. 4, pp. 643–654, 2005.

6 L. Horv´ath, “Generalizations of special Bihari type integral inequalities,” Mathematical Inequalities &

Applications, vol. 8, no. 3, pp. 441–449, 2005.

7 N. Lungu, “On some Gronwall-Bihari-Wendorff-type inequalities,” Fixed Point Theory, vol. 3, pp. 249–

254, 2002.

8 B. G. Pachpatte, “On generalizations of Bihari’s inequality,” Soochow Journal of Mathematics, vol. 31, no. 2, pp. 261–271, 2005.

9 B. G. Pachpatte, “Integral inequalities of the Bihari type,” Mathematical Inequalities & Applications, vol.

5, no. 4, pp. 649–657, 2002.

10 M. Pinto, “Integral inequalities of Bihari-type and applications,” Funkcialaj Ekvacioj, vol. 33, no. 3, pp.

387–403, 1990.

11 H. Ye, J. Gao, and Y. Ding, “A generalized Gronwall inequality and its application to a fractional differential equation,” Journal of Mathematical Analysis and Applications, vol. 328, no. 2, pp. 1075–1081, 2007.

12 W. Zhang and S. Deng, “Projected Gronwall-Bellman’s inequality for integrable functions,”

Mathematical and Computer Modelling, vol. 34, no. 3-4, pp. 393–402, 2001.

13 W.-S. Cheung, “Some discrete nonlinear inequalities and applications to boundary value problems for difference equations,” Journal of Difference Equations and Applications, vol. 10, no. 2, pp. 213–223, 2004.

14 W.-S. Cheung and J. Ren, “Discrete non-linear inequalities and applications to boundary value problems,” Journal of Mathematical Analysis and Applications, vol. 319, no. 2, pp. 708–724, 2006.

15 S. Deng and C. Prather, “Nonlinear discrete inequalities of Bihari-type,” submitted.

16 B. G. Pachpatte, “On Bihari like integral and discrete inequalities,” Soochow Journal of Mathematics, vol.

17, no. 2, pp. 213–232, 1991.

17 V. N. Phat and J. Y. Park, “On the Gronwall inequality and asymptotic stability of nonlinear discrete systems with multiple delays,” Dynamic Systems and Applications, vol. 10, no. 4, pp. 577–588, 2001.

18 J. Popenda and R. P. Agarwal, “Discrete Gronwall inequalities in many variables,” Computers &

Mathematics with Applications, vol. 38, no. 1, pp. 63–70, 1999.

19 L. Tao and H. Yong, “A generalization of discrete Gronwall inequality and its application to weakly singular Volterra integral equation of the second kind,” Journal of Mathematical Analysis and Applications, vol. 282, no. 1, pp. 56–62, 2003.

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20 F.-H. Wong, C.-C. Yeh, and C.-H. Hong, “Gronwall inequalities on time scales,” Mathematical Inequalities & Applications, vol. 9, no. 1, pp. 75–86, 2006.

21 B. G. Pachpatte, Integral and Finite Difference Inequalities and Applications, vol. 205 of North-Holland Mathematics Studies, Elsevier Science B.V., Amsterdam, The Netherlands, 2006.

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