The Consistency Of A Variant Of Church's Thesis With An Axiomatic Theory Of An Epistemic Notion. W.N. Reinhardt (1985) Revista colombiana de matematicas
The limit lemma in fragments of arithmetic Vítězslav Švejdar (2003) Commentationes Mathematicae Universitatis Carolinae The recursion theoretic limit lemma, saying that each function with a 𝛴 n + 2 graph is a limit of certain function with a 𝛥 n + 1 graph, is provable in B Σ n + 1 .