• 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 Section 3.10.3 and Section 3.10.4.
• See also: \[CapitalDelta] , \[PartialD] , \[Square] .