The method of lower and upper solutions for mixed fractional four-point boundary value problem with p-Laplacian operator

Based on the monotone iterative technique, a new method of lower and upper solutions which is used to study the multi-point boundary value problem of nonlinear fractional differential equations with mixed fractional derivatives and p-Laplacian operator is proposed. Some new results on the existence of positive solutions for the four-point boundary value problem are established. Finally, an example is presented to illustrate the wide range of potential applications of our main results.