Del
\[Del]
Alias: del. Prefix operator. f is by default interpreted as Del[f]. Used in vector analysis to denote gradient operator and its generalizations. Used in numerical analysis to denote backward difference operator. Also called nabla. Not the same as \[EmptyDownTriangle]. See The Mathematica Book: Section 3.10.3 and Section 3.10.4. See also: \[CapitalDelta] , \[PartialD] , \[Square] .