Editing Relevance logic (section)

==History==

Relevance logic was proposed in 1928 by Soviet philosopher [[Ivan E. Orlov]] (1886 – circa 1936) in his strictly mathematical paper "The Logic of Compatibility of Propositions" published in ''Matematicheskii Sbornik''. The basic idea of relevant implication appears in medieval logic, and some pioneering work was done by [[Wilhelm Ackermann|Ackermann]],<ref>
{{Citation
 | title = Begründung einer strengen Implikation
 | jstor = 2268750
 | year = 1956
 | first = W. | last =  Ackermann | author-link = Wilhelm Ackermann
 | journal = [[Journal of Symbolic Logic]]
 | pages = 113–128 | volume = 21 | issue = 2| doi = 10.2307/2268750
 }}
</ref> [[Moh Shaw-Kwei|Moh]],<ref>{{Citation
 | title = The Deduction Theorems and Two New Logical Systems
 | year = 1950
 | last = Moh  | first = Shaw-kwei
 | journal = Methodos
 | pages = 56–75 | volume = 2
}}
Moh Shaw-Kwei, 1950, "," Methodos 2 56–75.
</ref> and [[Alonzo Church|Church]]<ref>{{Citation
 | title = The Weak Theory of Implication
 | year = 1951
 | last = Church |first= A.
}} in ''Kontroliertes Denken: Untersuchungen zum Logikkalkül und zur Logik der Einzelwissenschaften'', Kommissions-Verlag Karl Alber, edited by A. Menne, A. Wilhelmy and H. Angsil, pp. 22–37.
</ref> in the 1950s. Drawing on them, [[Nuel Belnap]] and [[Alan Ross Anderson]] (with others) wrote the ''magnum opus'' of the subject, ''Entailment: The Logic of Relevance and Necessity'' in the 1970s (the second volume being published in the nineties). They focused on both systems of [[entailment]] and systems of relevance, where implications of the former kinds are supposed to be both relevant and necessary.