In this paper, we consider upper bound graphs and double bound graphs of posets. We obtain a characterization of upper bound graphs whose complements are also upper bound graphs as follows: for a connected graph G, both G and G are upper bound graphs if and only if G is a split graph with V(G)= K + S, where K is a clique and S is an independent set, satisfying one of the following conditions: (...

Monotone interpretations in the natural numbers provide a useful technique for proving termination of term rewriting systems. Termination proofs of this shape imply upper bounds on derivation lengths expressed in bounds on the interpretations. For a hierarchy of classes of interpretations we describe these upper bounds, among which the doubly exponential upper bound for polynomial interpretatio...

Fuzzy integral equations have a major role in the mathematics and applications.In this paper, general fuzzy integral equations with nonlinear fuzzykernels are introduced. The existence and uniqueness of their solutions areapproved and an upper bound for them are determined. Finally an algorithmis drawn to show theorems better.