3 papers
math.CO2021
Letter graphs and geometric grid classes of permutations
Bogdan Alecu, Robert Ferguson, Mamadou Moustapha Kanté +3
We uncover a connection between two seemingly unrelated notions: lettericity, from structural graph theory, and geometric griddability, from the world of permutation patterns. Both…
math.CO2021
Letter graphs and modular decomposition
Robert Ferguson, Vincent Vatter
We prove that if the prime graphs in a graph class have bounded lettericity, then the entire class has bounded lettericity if and only if it does not contain arbitrary large matchi…
math.CO2020
On the Lettericity of Paths
Robert Ferguson
Verifying a conjecture of Petkov{š}ec, we prove that the lettericity of an n-vertex path is precisely .