Phrase guide

regular open

adj · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

Sound

Pronunciation

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1

adj

Meaning 1

Being the interior of its closure.

Definition source: English Wiktionary via Wiktextract

Usage: not-comparable, rare

Topics: mathematics, sciences

Examples

  • The set (0,1)∪(1,2) is open, but is not regular open, because its closure is [0,2], so the interior of its closure is (0,2).

Meaning relationships

Synonyms: none provided

Antonyms: none provided

History

Etymology

From regular + open; apparently a backformation from regular open set.