Graceful Tree Conjecture for Infinite Trees
Tsz Lung Chan, Wai Shun Cheung, Tuen Wai Ng · The Electronic Journal of Combinatorics · 2009
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.