What ≗ means
It can mark any relation defined by that text. A 2016 math Q&A gives two uses: polynomials (expressions built from powers of a variable) sharing a root (a value that makes both zero), and theories with the same models (interpretations that make their statements true).
What older names are recorded?
The markup names are cire and circeq. A 2003 ISO 9573-13 draft lists both; a 2002 W3C MathML table also maps circeq to this character. A named entity is text a document uses for a special character. These tables name the character; each mathematical work defines its relation.
Don't confuse it with
1Questions people ask
1Why does ≗ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type ≗
≗\2257Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.
