MacLane, S. Abbreviated proofs in logic calculus. (English) JFM 60.0026.10 Bulletin A. M. S. 40, 37-38 (1934). Auszüge aus Mitteilungen an die American Mathematical Society Cited in 1 Document PDF BibTeX XML Cite \textit{S. MacLane}, Bull. Am. Math. Soc. 40, 37--38 (1934; JFM 60.0026.10)