Sylvester's Determinant Identity
where
is the submatrix of 
formed by the intersection of the subset 
of columns and 
of rows.- Digraph
- Dihedral Angle
- Dihedral Group
- Dijkstra's Algorithm
- Dijkstra Tree
- Dilation
- Dilemma
- Dilogarithm
- Dilworth's Lemma
- Dilworth's Theorem
- Dimension
- Dimensionality Theorem
- Dimension Axiom
- Dimension Invariance Theorem
- Diminished Polyhedron
- Diminished Rhombicosidodecahedron
- Dini Expansion
- Dini's Surface
- Dini's Test
- Dinitz Problem
- Diocles's Cissoid
- Diophantine Equation
- Diophantine Equation--10th Powers
- Diophantine Equation--5th Powers
- Diophantine Equation--6th Powers