principal type

Also found in: Wikipedia.

principal type

The most general type of an expression. For example, the following are all valid types for the lambda abstraction (\ x . x):

Int -> Int Bool -> Bool (a->b) -> (a->b)

but any valid type will be an instance of the principal type: a -> a. An instance is derived by substituting the same type expression for all occurences of some type variable. The principal type of an expression can be computed from those of its subexpressions by Robinson's unification algorithm.

This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

References in periodicals archive ?

Ethanol is, according to online encyclopedia Wikipedia, a "simple alcohol, the principal type of alcohol found in alcoholic drinks.

Eat it burnt and you're toast!

The principal type of stomata are polycytic but differs in being 10% diacytic and 10% anomocytic.

Polypodium vulgare subsp. melitense new subspecies from Gozo, Maltese Islands (Pteridophyta: Polypodiaceae)

MANOVA found significant differences in attachment style by Principal Type and Age Group.

Attachment Perspectives on Classroom Relationships: Helping Ourselves through Helping Others?

The expected fitness for principal type [P.sub.1] is [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII], and for [P.sub.2], it is [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII].

Putting agency and integrity to the test

Tax Withheld, and U.S.-Source Income, by Principal Type of Income, Selected Recipient Type, and Selected Country of Recipient, 2008 [Money amounts are in thousands of dollars] Selected country or Number U.S.

Foreign recipients of U.S. income, 2008

However, the principal type of rigour that the book inspires is the type known as mortis.

A Poverty of Reason: Sustainable Development and Economic Growth

The principal type of involvement the book aims at is hermeneutic, for although the title might suggest otherwise, Chafe does not employ analysis simply as a revealer of "purely musical" structure.

Analyzing Bach Cantatas

In the other principal type of regio errors, the insertion of the propylene occurs by a 1,3 insertion such that the section of the chain contains only incorporated methylene units.

Polyolefin elastomers with isotactic propylene crystallinity

The nature of the principal type 1 interferon-producing cells in human blood.

Interferon-producing plasmacytoid dendritic cells and the pathogenesis of AIDS

While credit cards remain the principal type of electronic payment in the United States in terms of the number and share of transactions, the use of debit cards is growing at a much faster rate.

Electronic Payments in the U.S. Economy: An Overview

Eighteen-Degree Water was first described by WHOI physical oceanographer Valentine Worthington in 1959 as one of the major water masses formed in the northern Sargasso Sea in late winter: It is the principal type of subtropical water found in the North Atlantic.

The Bermuda station S - a long-running oceanographic show: deeper waters show warming trend

(6.) In 1992, approximately 49 percent of those who used section 203Co) FHA loans (the principal type of FHA single-family loan program) were first-time homebuyers.

Residential lending to low-income and minority families: evidence from the 1992 HMDA data