Up Tack Symbol
⊥ (Up Tack) is a math symbol at U+22A5 used to mark a relation such as perpendicularity or incompatibility.
U+22A5
⊥ is the Unicode “Up Tack” symbol (U+22A5). It’s commonly seen in mathematical notation and typesetting. This page helps you copy, identify, and use it correctly.
Up Tack Symbol Meaning
The symbol ⊥, Unicode name “UP TACK” (U+22A5), is most often used in math and logic as a “bottom” or “contradiction/incompatibility” marker, depending on the notation system. In geometry and related fields, it is also used to indicate perpendicularity (the idea that something is orthogonal). In programming and formal systems, ⊥ can appear in documentation and diagrams to represent an undefined or bottom element in an ordering. Its exact interpretation can vary by context, so check the surrounding notation.
Common uses
- •Indicating perpendicular lines or orthogonality in geometry notes and diagrams
- •Marking a contradiction/inconsistency symbol in logic and proof writing
- •Representing a bottom/least element (⊥) in math and order-theory style explanations
- •Labeling an “undefined” or “no information” state in technical documentation
- •Using as a concise operator/symbol in typeset equations and educational materials
Examples
⊥ Up Tack Symbol (U+22A5)
- ⊥Line AB ⊥ Line CD
- ⊥If A and ¬A lead to ⊥, then the assumptions are inconsistent
- ⊥Let ⊥ be the least element in the lattice
- ⊥The system returns ⊥ when the value cannot be determined
- ⊥In the diagram, ⊥ marks the incompatible cases
Variations
Ready to copy
Technical codes
| Unicode | U+22A5 | |
| HTML Entity | ⊥ | |
| HTML Code | ⊥ | |
| CSS | \22A5 |
FAQ
What does the Up Tack symbol mean?
The symbol ⊥, Unicode name “UP TACK” (U+22A5), is most often used in math and logic as a “bottom” or “contradiction/incompatibility” marker, depending on the notation system. In geometry and related fields, it is also used to indicate perpendicularity (the idea that something is orthogonal). In programming and formal systems, ⊥ can appear in documentation and diagrams to represent an undefined or bottom element in an ordering. Its exact interpretation can vary by context, so check the surrounding notation.
What is the Unicode name and code point for ⊥?
The Unicode name is “UP TACK” and the code point is U+22A5.
How do I type ⊥ in HTML or CSS?
Use the HTML entity ⊥ in HTML. In CSS, you can use \\22A5.
Is ⊥ the same as a perpendicularity symbol?
Often yes in mathematical context, where ⊥ can indicate perpendicularity. However, it can also be used for “bottom/contradiction” depending on the notation.
What is the JavaScript escape for this character?
The JavaScript escape is \\u{22A5}.