🌐EnglishEnglishDeutschEspañolItalianoNederlandsPolskiPortuguêsSvenskaРусскийفارسی한국어中文日本語EntityQ1182249· pop 14· linked from 34 articlesdeduction theoremtheoremAvailable in 14 languagesEspañolDeutsch中文日本語РусскийPortuguêsItalianoPolskiSerbianSvenskaUkrainianConnectionspropositional calculusEntityfirst-order logicEntityCategoriesDeductive reasoningMetatheoremsProof theoryTheorems in the foundations of mathematics