first-order theory

first-order theory

[¦fərst ‚ȯrd·ər ′thē·ə·rē]

(mathematics)

A logical theory in which predicates are not allowed to have other functions or predicates as arguments and in which predicate quantifiers and function quantifiers are not permitted.

(optics)

Gaussian optics

(physics)

A theory which takes into account only the most important terms, such as the term proportional to the independent variable in the series expansion of a function appearing in the theory.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.