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Keywords from Image Description:
Fregegegenstze. en Diagram from of book Describes square of opposition for his system Taken from purely mechanical scan performed via gallica bnf fr some defects of the scan repaired by hand by myself Frege Gottlob Begriffsschrift eine der arithmetischen nachgebildete Formelsprache des reinen Denkens Halle Nebert Frege PDArt Begriffsschrift