Stability of fuzzy differential equations is one of the most important tasks in fuzzy set theory, since studying the behavior of the solution of the fuzzy differential system without solving the system explicitly fall into two categories:
Computing the volume and integral points of a polyhedron in 
is a very important subject in different areas of mathematics. There are two representations for the polyhedron, namely the H-representation and the V-representation. For each representation we give a different method of finding the volume and number of integral points. Moreover, the Ehrhart polynomial of a bounded polyhedron is discussed with some methods for finding it.
This thesis is concerned basically with establishing theoretical background for the Riemann-Liouville definition of fractional differentiation and integration of the function of several variables and solving certain type of fractional partial differential equations using some approximated methods.
