What ⨨ means
A custom “plus-like” operation that the author defines. Mathematicians often need several kinds of combining at once, and a decorated plus says “this is addition, but not the ordinary one.” Unicode encodes seven such variants side by side, from to ⨨, each telling itself apart only by the small mark attached to the plus; ⨨ is the one with a solid black triangle.
It came from the STIX project, a joint effort of scientific publishers to collect every symbol found in their journals, which proposed it in 2000 as “filled triangle with plus”. The MathML standard for formulas on the web lists it as an infix operator, meaning it sits between two expressions: a ⨨ b. If you meet it in a paper, look for the line where the author defines it.
Part of collections
Don't confuse it with
2
Related characters
2
Questions people ask
2Is ⨨ a Christian or occult cross?
No. It looks a little like a cross on a stand or an arrow, but it is a maths operator: a plus sign with a triangle mark.
Can I use it instead of in normal sums?
No. Readers would expect a special operation; use the ordinary for everyday addition.
More like this
9
How to type or find ⨨
- Also called
- plus with filled triangle · plustrif
- Search it as
- plus triangle · plus sign triangle · \plustrif · U+2A28 · plus with arrow · math operator
- Shows up in
- Anything that takes text · its shape is whatever your font draws
⨨\2A28\plustrif in math mode.Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.