(logic, model theory) The ⊨ symbol used to denote semantic consequence, or the ⊨ symbol used to denote the fact that the model to the left of it satisfies the set of sentences to its right.

plural of memorandum

(informal) Sexual perversion.

Refers to the orbit of a satellite whose rate of revolution is matched to the rotation period of the Earth. A special case is the geostationary orbit which is circular and equatorial, so that the s...