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Ivan Efimovič Orlov’s paper “The calculus of the compatibility of propositions”, published in Russian in 1928, is fascinating for anyone interested in the early history of relevance, modal or intuitionistic logic. This is a guide that outlines Orlov's life and work, analyses the content of the paper, and relates it to work of his contemporaries and successors.
Makinson et al. (Wed,) studied this question.