Григорьев, Валентин Дмитриевич. “Eefficiency Comparison of Iimplementations of Inference Algorithm for Sequent Propositional Calculus in Refal-5 and Haskell.”. Computer Tools in Education0, no. 6 (December 30, 2015): 19-33. Accessed April 23, 2024. http://cte.eltech.ru/ojs/index.php/kio/article/view/1448.