# Glossary

From Ontohub

Term | Description |
---|---|

Logical theory | set of expressions (like non-logical symbols, sentences and structuring elements) in a given logical language |

Alignment | flexible, relational link that does not always have a formal, logic-based semantics |

Matching | algorithmic procedure that generates an alignment for two given logical theories |

Logical language | language that is used for writing down logical theories (e.g. formal ontologies, models and specification), equipped with a formal, declarative, logic-based semantics, plus non-logical annotations |

Mapping | relationship between two logical theories, relating their non-logical symbols |

Language translation | mapping from constructs in the source logical language to their equivalents in the target logical language |

Interpretation | logical link that postulates a relation between two logical theories |

Combination | aggregation of several logical theories along links to a new logical theory where (only) the linked non-logical symbols of the involved logical theeories are identified |

Conservativity | property of an extension of theories, ensuring that the extension does not add new logical context |

Basic logical theory | set of non-logical symbols, sentences, annotations about them, which is used as a building block for a larger logical theory |

Axiom | sentence postulated to be valid (i.e. true in every model), party of a logical theory |

Theorem | sentence that has been proven (in some logical theory) from other axioms and theorem |

Structured logical theory | logical theory that results from other logical theories by import, union, combination, renaming or other structuring operations |

Sentence | term that is either true or false in a given model, i.e. which is assigned a truth value in this model |

Satisfaction relation | relation between models and sentences indicating which sentences hold true in the model |

Non-logical symbol | atomic expression or syntactic constituent of a logical theory that requires an interpretation through a model |

Module extraction | activity of obtaining from anlogical theory concrete modules to be used for a particular purpose (e.g. to contain a particular sub-signature of the original logical theory) |

Module | subtheory that conservatively extends to the whole logical theory |

Model | semantic interpretation of all non-logical symbols of a logical theory, satisfying the theory's axioms |

Approximation | reduction of a theory to a less expressive logical language, such that the original theory implies the approximation |