einull

Einull is a coinage that has appeared in online glossaries and speculative discussions to denote a value that is both absent and yet associated with a possible future state. It is not a term with formal status in mathematics, computer science standards, or linguistics. The etymology is informal, combining 'ein'—a German indefinite article meaning 'a' or 'one'—with 'null' to suggest a single, missing value.

In hypothetical programming contexts, einull might designate a sentinel that differs from a standard null by implying that initialization or content will be provided later. It could be used in models of lazy initialization or staged computation where a variable is known to require content, but is currently empty. In theoretical discussions on truth-value and reference, einull has been used as a thought experiment to explore referentiality when content is not yet determined. In speculative fiction and hobbyist notation, the term has occasionally appeared as the name of an artifact or entity that exists as potential rather than actual.

Relation to other concepts: it is related to null, undefined, NaN, and sentinel values, but it is not interchangeable with them in formal contexts. The term remains informal and non-standard, with varying meanings across communities.

See also: Null value, Undefined, NaN, Sentinel value.