Adjective
(mathematics, in optimization programming) Involving a finite number of variables but an infinite number of constraints, or vice versa.
(ballistics, of a target) Sufficiently thick that the level of penetration of a projectile is not affected by its thickness.
Limited at one end but extending to infinity in the other direction.
Source: en.wiktionary.orgAn example of a collection of open sets which is not a base is the set S of all semi-infinite intervals of the forms (−∞, a) and (a, ∞), where a is a real number. Source: Internet
In addition to these components, an oracle machine also includes: * an oracle tape, which is a semi-infinite tape separate from the work tape. Source: Internet