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Giuseppe Peano and so on, did not use as non-equivalence literally which is possibly because it could be defined from negation and equivalence easily.
* was used by Giuseppe Peano in 1894: ". The sign corresponds to Latin aut; the sign to vel." Note that the Latin word "aut" means "exclusive or" and "vel" means "inclusive or", and that Peano use as inclusive disjunction.
* was used by Izrail Solomonovich Gradshtein (??????? ??????????? ?????????) in

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