plural of formation rule

plural of inference rule

(logic, proof theory) A rule for combining (or modifying) well-formed formulas of a formal language in a truth-preserving manner (to yield new well-formed formulas).

plural of ground rule

(trigonometry) law of cosines

(trigonometry) law of sines

(chemistry) A rule in chemistry that states that the sum of the hydrogen valence and the maximum oxygen valence is equal to eight.

(obsolete) Algebra.

(gematria, very rare in print) The rule according to which one digit may be added to or subtracted from the gematric value of a word.

The ecogeographic principle that, within a broadly distributed taxonomic clade, populations and species of larger size are found in colder environments, and species of smaller size are found in warmer regions.