This article is a short explanation of some of the results obtained in my papers “On refined enumerations of totally symmetric self-complementary plane partitions I, II”. We give Pfaffian expressions for some of the conjectures in the paper “Self-complementary totally symmetric plane partitions” (J. Combin. Theory Ser. A 42, 277–292) by Mills, Robbins and Rumsey, using the lattice path method.

We define the Cartesian product, composition, union and join on interval-valued fuzzy graphs and investigate some of their properties. We also introduce the notion of interval-valued fuzzy complete graphs and present some properties of self complementary and self weak complementary interval-valued fuzzy complete graphs.

We prove that a trinucleotide circular code is self-complementary if and only if its two conjugated classes are complement of each other. Using only this proposition, we prove that if a circular code is self-complementary then either both its two conjugated classes are circular codes or none is a circular code.

In this paper, we introduce the concept of an intuitionistic fuzzy graph structure (IFGS). We discuss certain notions, including intuitionistic fuzzy Bi-cycles, intuitionistic fuzzy Bi-trees and φ-complement of an intuitionistic fuzzy graph structure with several examples. We also present φ-complement of an intuitionistic fuzzy graph structure along with self-complementary and strong self-compl...