Multiply Connected
A set which is Connected but not Simply Connected is called multiply connected. A Spaceis 
-Multiply Connected if it is 
-connected and if every Map from the -Sphere into it extendscontinuously over the 
-Disk
A theorem of Whitehead says that a Space is infinitely connected Iff it is contractible.
See also Connectivity, Locally Pathwise-Connected Space,Pathwise-Connected, Simply Connected- Degree of Freedom
- Degree (Polynomial)
- Degree Sequence
- Degree (Vertex)
- Dehn Invariant
- Dehn's Lemma
- Dehn Surgery
- de Jonquières Theorem
- de Jonquières Transformation
- Del
- de la Loubere's Method
- Delannoy Number
- Delaunay Triangulation
- Delian Constant
- Delian Problem
- de Longchamps Point
- Del Pezzo Surface
- Delta Amplitude
- Delta Curve
- Delta Function
- Deltahedron
- Delta Sequence
- Delta Variation
- Deltoid
- Deltoidal Hexecontahedron