In this paper the substantiation of the method of full averaging for fuzzy differential inclusions is considered. These results generalize the results of [17, 20] for differential inclusions with Hukuhara derivative and of [18] for fuzzy differential equations.

In this paper, the variational iteration method for solving nth-order fuzzy integro-differential equations (nth-FIDE) is proposed. In fact the problem is changed to the system of ordinary fuzzy integrodifferential equations and then fuzzy solution of nth-FIDE is obtained. Some examples show the efficiency of the proposed method.

The existence of fixed point in partially ordered sets has been studied and investigated recently in 1–13 and references therein. Since the various contractive conditions are important in metric fixed point theory, there is a trend to weaken the requirement on contractions. Nieto and Rodrı́guez-López in 8, 10 used Tarski’s theorem to show the existence of solutions for fuzzy equations and fuzzy ...