The subdivision graph of a graceful tree is a graceful tree

Graceful Tree Labeling

Towards the Graceful Tree Conjecture: A Survey

A graceful labelling of an undirected graph G with n edges is a one-to-one function from the set of vertices of G to the set {0, 1, 2, . . . , n} such that the induced edge labels are all distinct. An induced edge label is the absolute value of the difference between the two end-vertex labels. The Graceful Tree Conjecture states that all trees have a graceful labelling. In this survey we presen...

Embedding an Arbitrary Tree in a Graceful Tree

A function f is called a graceful labeling of a graph G with m edges if f is an injective function from V (G) to {0, 1, 2, · · · ,m} such that when every edge uv is assigned the edge label |f(u)− f(v)|, then the resulting edge labels are distinct. A graph which admits a graceful labeling is called a graceful graph. The popular Graceful Tree Conjecture states that every tree is graceful. The Gra...

Graceful Tree Conjecture for Infinite Trees

One of the most famous open problems in graph theory is the Graceful Tree Conjecture, which states that every finite tree has a graceful labeling. In this paper, we define graceful labelings for countably infinite graphs, and state and verify a Graceful Tree Conjecture for countably infinite trees.

A Computational Approach to the Graceful Tree Conjecture

Graceful tree conjecture is a well-known open problem in graph theory. Here we present a computational approach to this conjecture. An algorithm for finding graceful labelling for trees is proposed. With this algorithm, we show that every tree with at most 35 vertices allows a graceful labelling, hence we verify that the graceful tree conjecture is correct for trees with at most 35 vertices.