Vel (∨) (vel is "or" in Latin) or descending wedge is a symbol used to represent:
It was used by Russell and Whitehead in Principia Mathematica, where they called it the Logical Sum or Disjunctive Function. In Unicode the symbol is encoded U+2228 ∨ Logical or (HTML ∨ ·  ∨) and by \vee and \lor in TeX. The opposite symbol (∧) is called a wedge.
References
Vel (symbol) Wikipedia(Text) CC BY-SA
