EntityQ837518· pop 30· linked from 430 articlesalphabetSign in to savenon-empty set of symbols or letters that make up strings in a formal languageConnectionsformal languageEntitysemantic theory of truthEntitymathematical logicEntitysequenceEntitystringEntitycountable setEntityfirst-order logicEntityuncountable setEntityformal systemEntityrecursive setEntitysemantics of logicEntitystructureEntityground expressionEntitydiagramEntityNew York CityCitylogicEntityInternational Standard Book NumberEntityQ15777EntityalgorithmEntityset theoryEntityCategoriesCombinatorics on wordsFormal languages