Double superset (⋑) is the Unicode character at U+22D1 in the Mathematical Operators block. Official name: DOUBLE SUPERSET. It is used in set theory and mathematical notation for a double-superset relation.
Remember
Character ⋑
Unicode U+22D1
Named entity ⋑
Hex entity ⋑
Decimal ⋑
CSS escape \22D1
Not the same ⊃ (⊃) · ⋐ (⋐)
Prefer ⋑ in HTML markup (capital S; also aliased as ⋑). You can also type ⋑ in UTF-8, or use numeric forms when needed.
Double Superset using Named Entity: ⋑
Double Superset using Hex Code: ⋑
Double Superset using HTML Code: ⋑
Double Superset using CSS Entity: ⋑
Typed directly: ⋑
Compared: A ⋑ B vs A ⊃ B
How It Works
1. Named:⋑ is the HTML5 name for U+22D1 → ⋑. Best default in markup (capital S; also ⋑).
2. Hex:U+22D1 → ⋑ in HTML. Same glyph as the named form.
3. Decimal: same code point as 8913 → ⋑. Same result as hex and named.
4. CSS: use \22D1 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 superset.
Pitfalls & Tips
Common mistakes when working with Double Superset.
Case
Capital S matters
⋑ is double superset (⋑). ⊃ is ordinary superset (⊃). The names are case-sensitive.
⊃
Not ordinary superset
For everyday set containment, prefer ⊃. Use ⋑ only when you specifically need the double-superset glyph.
⋐
Pair with ⋐
The matching opposite relation is double subset ⋐ (U+22D0).
Alias
Longer name works too
⋑ is an HTML5 alias for the same character as ⋑. Prefer the short form in everyday markup.
CSS vs HTML
Do not mix escapes
\22D1 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 &Sup.
Compatibility
Browser Support
Double superset (U+22D1) and its entity forms (⋑, ⋑, ⋑, CSS \\22D1) are supported in all mainstream browsers. Visible glyphs depend on math / operator font coverage.
✓ Universal support
Double Superset (⋑)
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+22D1 / entitiesFull support
Bottom line: Prefer ⋑ in HTML. Use ⋑ / ⋑ when numeric form is required, and \\22D1 only inside CSS content.
Remember
Key Takeaways
Unicode: double superset is U+22D1 (decimal 8913) — glyph ⋑.
HTML: prefer ⋑ — also ⋑ / ⋑ / type ⋑.
CSS: use \22D1 inside content for generated text.
Meaning:⋑ = double superset — not ⊃, not ⋐.
Use ⋑ (named), ⋑ (hex), ⋑ (decimal), type ⋑ directly in UTF-8, or the CSS escape \22D1 in content. Prefer ⋑ in normal HTML.
U+22D1 (DOUBLE SUPERSET). Hex 22D1, decimal 8913. It belongs to the Mathematical Operators block (U+2200–U+22FF).
Yes. Use ⋑ (capital S) or the alias ⋑. Numeric forms ⋑ and ⋑ also work. Do not use ⊃ — that is ordinary superset U+2283.
Use it in set-theory or math text when you need the double-superset relation ⋑. Prefer ⊃ for ordinary superset ⊃, and ⋐ for double subset ⋐.
HTML entities (⋑, ⋑, or ⋑) go in markup. The CSS escape \22D1 goes in stylesheet strings (usually content on ::before/::after).
⋑ and ⋑ both decode to ⋑ (U+22D1). ⊃ is ⊃ (U+2283) — a different character. Entity names are case-sensitive.
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Did you know?
Double superset is Unicode U+22D1 (decimal 8913) — glyph ⋑ in the Mathematical Operators block. HTML5 names it ⋑ (also ⋑). Ordinary superset is ⊃ (U+2283). The matching double-subset is ⋐ (U+22D0).
