deduction | W known, O queried or tested |

induction | W has incomplete rules |

abduction | W has incomplete facts |

normality | W incomplete, but "normal" thus can be completed |

analogy | W to O incomplete, but analogous W' to O' is known |

probabilistic | W unsure, probabilistic information available |

vague | W and O vague |

diagnose | W to B unknown, but correct W' to normal O' is known |

planning | W is sensitive for resources |

space, time | W is domainspecific |

Most general inference relations are these:

- ⊢
*deduces*: the deduction relation is true if a formula deduced (*conclusion*), can be proven on the basis of more general knowledge. The knowledge deduced is true. For classical logic systems, this relation is sometimes called logic sequence (⊨). - ≺
*induces*: the induction relation is true if a formula induced (*hypothesis-rule*), fits with all examples of the formulas. The rule formula induced does not need to be true for other examples. - ≻
*abduces*: the abduction relation is true if a formula abduced (*hypothesis-cause*), explains a factual formula on the basis of the general knowledge formulas (rules).

Be aware that in another context, the relation ≺ is called subsumption where s ≺ g is true if s is more special than g.