Double union (⋓) is the Unicode character at U+22D3 in the Mathematical Operators block. Official name: DOUBLE UNION. It is used in set theory and mathematical notation for a double-union operator.
Remember
Character ⋓
Unicode U+22D3
Named entity ⋓
Hex entity ⋓
Decimal ⋓
CSS escape \22D3
Not the same ∪ (∪) · ⋒ (⋒) · ⋃ (⋃)
Prefer ⋓ in HTML markup (capital C). You can also type ⋓ in UTF-8, or use numeric forms when needed.
Double union rendered alone and compared with related set operators.
ExampleA ⋓ B
Large glyph⋓
Compared⋓ ∪ ⋒ ⋃
With entitiesNamed: ⋓ | Hex: ⋓ | Decimal: ⋓
Code
Complete HTML Example
One page that shows Double Union with named, hex, decimal, CSS escape, and a typed character. Use View Output or open the live editor.
Named + Hex + Decimal + CSS + Typed
Five ways to produce ⋓, plus a comparison with ordinary ∪.
html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Double Union (⋓) in HTML</title>
<style>
#point::after {
content: "\22D3";
}
</style>
</head>
<body>
<p>Double Union using Named Entity: ⋓</p>
<p>Double Union using Hex Code: ⋓</p>
<p>Double Union using HTML Code: ⋓</p>
<p id="point">Double Union using CSS Entity: </p>
<p>Typed directly: ⋓</p>
<p>Compared: A ⋓ B vs A ∪ B</p>
</body>
</html>
Double Union using Named Entity: ⋓
Double Union using Hex Code: ⋓
Double Union using HTML Code: ⋓
Double Union using CSS Entity: ⋓
Typed directly: ⋓
Compared: A ⋓ B vs A ∪ B
How It Works
1. Named:⋓ is the HTML5 name for U+22D3 → ⋓. Best default in markup (capital C).
2. Hex:U+22D3 → ⋓ in HTML. Same glyph as the named form.
3. Decimal: same code point as 8915 → ⋓. Same result as hex and named.
4. CSS: use \22D3 in content (not an HTML entity). #point::after appends that ⋓ after the paragraph text.
5. Typed / compared: paste ⋓ in UTF-8, or write A ⋓ B vs A ∪ B to contrast double and ordinary union.
Pitfalls & Tips
Common mistakes when working with Double Union.
Case
Capital C matters
⋓ is double union (⋓). ∪ is ordinary union (∪). The names are case-sensitive.
∪
Not ordinary union
For everyday set union, prefer ∪. Use ⋓ only when you specifically need the double-union glyph.
⋒
Pair with ⋒
The matching double-intersection operator is ⋒ (U+22D2).
⋃
Not ⋃
⋃ / ⋃ is n-ary union (U+22C3) — the large “big cup” operator, not double union.
CSS vs HTML
Do not mix escapes
\22D3 belongs in CSS strings. ⋓ / ⋓ / ⋓ belong in HTML.
Fonts
Math font coverage
Some fonts omit less-common Mathematical Operators. Prefer a math-capable font for reliable display of ⋓.
Semicolon
End named entities
Always finish with ; — write ⋓, not &Cup.
Compatibility
Browser Support
Double union (U+22D3) and its entity forms (⋓, ⋓, ⋓, CSS \\22D3) are supported in all mainstream browsers. Visible glyphs depend on math / operator font coverage.
✓ Universal support
Double Union (⋓)
Encode with named, hex, decimal, CSS escape, or type the character — same code point everywhere encoding is supported.
100%Browser coverage
Google ChromeSupported
Yes
Microsoft EdgeSupported
Yes
Mozilla FirefoxSupported
Yes
Apple SafariSupported
Yes
OperaSupported
Yes
Internet ExplorerAll versions
Yes
U+22D3 / entitiesFull support
Bottom line: Prefer ⋓ in HTML. Use ⋓ / ⋓ when numeric form is required, and \\22D3 only inside CSS content.
Remember
Key Takeaways
Unicode: double union is U+22D3 (decimal 8915) — glyph ⋓.
HTML: prefer ⋓ — also ⋓ / ⋓ / type ⋓.
CSS: use \22D3 inside content for generated text.
Meaning:⋓ = double union — not ∪, not ⋒, not ⋃.
Use ⋓ (named), ⋓ (hex), ⋓ (decimal), type ⋓ directly in UTF-8, or the CSS escape \22D3 in content. Prefer ⋓ in normal HTML.
U+22D3 (DOUBLE UNION). Hex 22D3, decimal 8915. It belongs to the Mathematical Operators block (U+2200–U+22FF).
Yes. Use ⋓ (capital C). Numeric forms ⋓ and ⋓ also work. Do not use ∪ — that is ordinary union U+222A.
Use it in set-theory or math text when you need the double-union operator ⋓. Prefer ∪ for ordinary union ∪, ⋒ for double intersection ⋒, and ⋃ for n-ary union ⋃.
HTML entities (⋓, ⋓, or ⋓) go in markup. The CSS escape \22D3 goes in stylesheet strings (usually content on ::before/::after).
No. ⋓ is ⋓ (U+22D3). ∪ is ∪ (U+222A). ⋃ is ⋃ (U+22C3). Entity names are case-sensitive.
🤔
Did you know?
Double union is Unicode U+22D3 (decimal 8915) — glyph ⋓ in the Mathematical Operators block. HTML5 names it ⋓ (capital C). Ordinary union is ∪ (U+222A). The matching double-intersection is ⋒ (U+22D2). N-ary union is ⋃ (U+22C3).
