⧺

⧺

1. (mathematics) Of strings, lists, vectors, or matrices, concatenated with.

   ${\displaystyle [0,1,2]\mathbin {+\!\!\!+} [3,4,5]=[0,1,2,3,4,5].}$

2. (programming, rare outside of handwritten code) Ligature of ++.

• ++
• +
• ⧻
• ∥ (“concatenated with”)