vahemikesse

Vahemikesse is the illative form of the Estonian noun vahemik, which denotes an interval or range of values. In mathematical and analytical writing, vahemik refers to any continuous set of numbers between two endpoints, such as an open, closed, or half-open interval.

Vahemikesse marks movement into that interval or inclusion within it and is used in contexts where Estonian syntax requires an illative case to indicate “into the interval.” The form is part of standard Estonian grammar: the noun vahemik takes the illative ending -sse to form vahemikusse.

In practice, many writers prefer a prepositional construction like vahemiku sisse, so vahemikusse appears most often in formal, compact notation or technical prose. Open interval is called avatud vahemik; closed interval is suletud vahemik; half-open interval is poolavatud vahemik.

The term is primarily used in mathematical, statistical, and data-analytic contexts, where precise descriptions of value ranges and constraints are required. It is less common outside technical writing, but it forms part of the broader vocabulary surrounding intervals and ranges in Estonian. See also vahemik (interval) and related terms for interval types and notation.