DifferentialRoot[lde] represents a function that solves the linear differential equation specified by lde[y, x].
DifferentialRootReduce[expr, x] attempts to reduce expr to a single DifferentialRoot object as a function of x.DifferentialRootReduce[expr, {x, x_0}] takes the initial ...
DigitBlock is an option for NumberForm and related functions that specifies the maximum length of blocks of digits between breaks.
DigitCharacter represents a digit character 0\[Dash]9 in StringExpression.
DigitCount[n, b, d] gives the number of d digits in the base-b representation of n. DigitCount[n, b] gives a list of the numbers of 1, 2, ..., b - 1, 0 digits in the base-b ...
DigitQ
(Built-in Mathematica Symbol) DigitQ[string] yields True if all the characters in the string are digits in the range 0 through 9, and yields False otherwise.
DihedralGroup[n] represents the dihedral group of order 2 n.
Dilation[image, ker] gives the morphological dilation of image with respect to the structuring element ker.Dilation[image, r] gives the dilation with respect to a range r ...
Dimensions[expr] gives a list of the dimensions of expr. Dimensions[expr, n] gives a list of the dimensions of expr down to level n.
DiracComb[x] represents the Dirac comb function giving a delta function at every integer point. DiracComb[x_1, x_2, ...] represents the multidimensional Dirac comb function.