The existence of solutions for nonlinear multipoint

boundary value problems have been investigated by many authors.

into an integral equation which will be used to define the solution of the

boundary value problem (5).

As an example of solving

boundary value problems using RBFN, learned by TRM, consider the

boundary value problem for the two-dimensional Poisson equation, described in [8]

We are interested here in convex and convex-concave solutions of the

boundary value problem [P.sub.[lambda](a, b)].

Cui, "Positive solutions for

boundary value problems of fractional differential equation with integral boundary conditions," Journal of Function Spaces, vol.

Firstly, we mainly pay close attention to the stability of the weak solutions based on the partial

boundary value conditions.

For the first form of the finite difference filter, we apply the central finite differences to obtain a discretization of the nonlinear fourth-order

boundary value problem.

The outcomes in this paper concern both the analytical results and numerical solutions study of first-order nonlocal singularly perturbed

boundary value problem.

Although there are few results for existence and uniqueness of

boundary value problems of sequential fractional derivative by using standart fixed point theorems, such as the method of upper and lower solutions and Schauder fixed point theorem [28], contraction principle [19], the method of upper and lower solutions and its associated monotone iterative method [4], Banach's contraction mapping principle, Krasnoselskii's fixed point theorem and nonlinear alternative of Leray-Schauder type [3, 2], as far as we know there is not much done by using Lyapunov type inequality and disconjugacy criterion.

In the past few decades, the

boundary value methods (BVMs) have been used to solve first-order initial and

boundary value problems [4-8].

In [29], the authors studied the following nonlinear semipositone fractional differential equation with four-point coupled

boundary value problem: