EntityQ748349· pop 41· linked from 129 articlesmathematical structureSign in to savecombination of a set and an extra structure on it; more precisely, an object of a concrete categoryConnectionssemantic theory of truthEntitymathematical logicEntityfirst-order logicEntityformal systemEntityrecursive setEntitysemantics of logicEntitystructureEntityground expressionEntitydiagramEntitymathematicsEntitygeometryEntitylogicEntityInternational Standard Book NumberEntityset theoryEntityfunctionEntitylengthEntityreal numberEntitysetEntityaxiomEntitydigital object identifierEntityCategoriesMathematical structuresSet theoryType theory