What ⊓ means
It combines two elements by selecting their greatest lower bound. A lattice is an ordered system where each pair has a greatest lower bound and a least upper bound. “Lattice meet” and “sqcap” name the first operation.
Is ⊓ the same as set intersection?
Only in a lattice of sets ordered by containment. There, the meet is the intersection: the set of elements present in both inputs. For a general lattice, ⊓ still denotes the greatest lower bound, while ∩ may not apply.
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 ⊓
Windows (Word)
Alt+XType 2293, then Alt+X to get ⊓.
Windows
Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win + .).
macOS
Control+Command+SpaceOpen the character viewer and search “square cap”.
Linux
Ctrl+Shift+UType 2293, then Enter or Space.
HTML
⊓CSS
\2293Codes and encoding1 code points
HTML decimal
⊓
HTML hex
⊓
CSS content
content: "\2293";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%8A%93
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.