EntityQ1149458· pop 17· linked from 352 articlescompactness theoremSign in to savetheoremConnectionsfirst-order logicEntitystructureEntitysemantic theory of truthEntitymathematical logicEntityinjectionEntitysurjective functionEntityPeano axiomsEntityformal systemEntityrecursive setEntityLöwenheim–Skolem theoremEntitysemantics of logicEntitydiagramEntityground expressionEntitylogicEntityInternational Standard Book NumberEntitycomplex numberEntityset theoryEntityfunctionEntitysetEntityaxiomEntityCategoriesMathematical logicMetatheoremsModel theoryTheorems in the foundations of mathematics