# Irrationality of Catalan’s constant The following describes the scope of the Lean formalization related to the following accompanying paper(s): - [Catalan's constant is irrational](../../preprints/Catalans-constant-is-irrational-September-24-2026/paper.pdf) ## Scope The formalization proves that Catalan's constant $G=\sum_{j=0}^{\infty}(-1)^j/(2j+1)^2$ is irrational. This is the mathematical assertion in the paper's title. ## Comparator links | Result | Comparator statement | | --- | --- | | Irrationality of Catalan's constant | [Catalan.lean](../ComparatorChallenges/Catalan.lean) |