sale

n 1: the general activity of selling; "they tried to boost

sales"; "laws limit the sale of handguns"

2: a particular instance of selling; "he has just made his

first sale"; "they had to complete the sale before the

banks closed"

3: the state of being purchasable; offered or exhibited for

selling; "vitamin C is on sale at most pharmacies"; "the

new line of cars will soon be on sale"

4: an occasion (usually brief) for buying at specially reduced

prices; "they held a sale to reduce their inventory"; "I

got some great bargains at their annual sale" [syn: {cut-rate

sale}, {sales event}]

5: an agreement (or contract) in which property is transferred

from the seller (vendor) to the buyer (vendee) for a fixed

price in money (paid or agreed to be paid by the buyer);

"the salesman faxed the sales agreement to his home

office" [syn: {sales agreement}]

safe

A safe program analysis is one which will not reach invalid

conclusions about the behaviour of the program. This may

involve making safe approximations to properties of parts of

the program. A safe approximation is one which gives less

information.

For example, strictness analysis aims to answer the question

"will this function evaluate its argument"?. The two possible

results are "definitely" and "don't know". A safe

approximation for "definitely" is "don't know". The two

possible results correspond to the two sets: "the set of all

functions which evaluate their argument" and "all functions".

A set can be safely approximated by another which contains it.