reaction

n 1: a response that reveals a person's feelings or attitude; "he

was pleased by the audience's reaction to his

performance"; "John feared his mother's reaction when

she saw the broken lamp"

2: a bodily process occurring due to the effect of some

foregoing stimulus or agent; "a bad reaction to the

medicine"; "his responses have slowed with age" [syn: {response}]

3: an idea evoked by some experience; "his reaction to the news

was to start planning what to do"

4: (chemistry) a process in which one or more substances are

changed into others; "there was a chemical reaction of the

lime with the ground water" [syn: {chemical reaction}]

5: doing something in opposition to another way of doing it

that you don't like; "his style of painting was a reaction

against cubism"

6: extreme conservatism in political or social matters; "the

forces of reaction carried the election"

7: (mechanics) the equal and opposite force that is produced

when any force is applied to a body; "every action has an

equal and opposite reaction"

reduction

(Or "contraction") The process of transforming an expression

according to certain reduction rules. The most important

forms are {beta reduction} (application of a {lambda

abstraction} to one or more argument expressions) and {delta

reduction} (application of a mathematical function to the

required number of arguments).

An {evaluation strategy} (or {reduction strategy}), determines

which part of an expression (which redex) to reduce first.

There are many such strategies.

See {graph reduction}, {string reduction}, {normal order

reduction}, {applicative order reduction}, {parallel

reduction}, {alpha conversion}, {beta conversion}, {delta

conversion}, {eta conversion}.

(1995-02-21)