The Multiset Union symbol (⊎). Copy and paste it, or use its Unicode, HTML, and CSS codes.
More from Math.
The quickest way is to copy ⊎ from this page and paste it anywhere. You can also insert it with its Unicode, HTML, or alt code listed above.
⊎ is U+228E (decimal 8846).
Use ⊎ in HTML to render ⊎ on a web page.
On Windows you can type it with Alt+8846 (hold Alt and enter the number on the numeric keypad).
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