(calculus) A formula for computing the derivative of the functional composition of two or more functions.

A scale marked with numbers for finding without calculation the number of square feet in a board.

(printing, historical) A fine, thin, short metal rule of the same height as the type, used in printing short lines in tabular matter.

Ampère's circuital law

(rail transport) The steepest uphill gradient in one direction on a section of railway line, which determines the load that can be pulled by one locomotive over that section, according to the power rating of the locomotive. A typical ruling gradient could be 1:50 (2%). The ruling gradient can differ in the other direction on the same section.

The recommendation that a person should drink eight servings of eight ounces of water each day.

plural of ruling gradient

(law) The absence of rule of law in which one person, or a group of persons, rules arbitrarily.

An empirical rule for predicting the favoured alkene product(s) in elimination reactions. The alkene formed in greatest amount is the one that corresponds to removal of the hydrogen from the β-carbon having the fewest hydrogen substituents.

The rule that social parasites generally tend to be parasites of species or genera to which they are closely related.