3-D Graphics overview: does MeshGeometry sample code match the explanation?

I read the 3-D Graphics Overview (http://msdn.microsoft.com/en-us/library/ms747437(VS.100).aspx) and I'm confused about this section that explains the MeshGeometry3D shown in the sample code.  I've included the statements below in order to ask my question:

"Each vertex is specified as a Point3D (Represents an x-, y-, and z-coordinate point in 3-D space).  (In Extensible Application Markup Language (XAML), specify this property as a list of numbers grouped in threes that represent the coordinates of each vertex.) Depending on its geometry, your mesh might be composed of many triangles, some of which share the same corners (vertices). "

          <MeshGeometry3D
              Positions="-1 -1 0  1 -1 0  -1 1 0  1 1 0"
              Normals="0 0 1  0 0 1  0 0 1  0 0 1"
              TextureCoordinates="0 1  1 1  0 0  1 0  "
              TriangleIndices="0 1 2  1 3 2"/>

"In the preceding example, the Positions list specifies eight vertices to define a cube-shaped mesh. TheTriangleIndices property specifies a list of twelve groups of three indices.  Each number in the list refers to an offset into thePositions list.  For example, the first three vertices specified by thePositions list are (1,1,0), (0,1,0), and (0,0,0). The first three indices specified by theTriangleIndices list are 0, 2, and 1, which correspond to the first, third, and second points in thePositions list. As a result, the first triangle that makes up the cube model will be composed from (1,1,0) to (0,1,0) to  (0,0,0), and the remaining eleven triangles will be determined similarly."

QUESTIONS:

1. How does the Positions list specify 8 vertices (A vertex (plural:vertices) is a point where two or more straight lines meet). Is it counted as follows:

(1) x1,y1  (2) x-1,y-1 (3) x1,y-1 (4) x-1, y1  (5) x1, z0 (6) x-1, z0 (7) y1, z0 (8) y-1, z0?

2.   How does the TriangleIndices property specify a list of 12 GROUPS of 3 indices?  The statement says "the first 3 vertices specified by thePositions list are (1,1,0), (0,1,0), and (0,0,0)" - I don't see 0,1,0 or 0,0,0 in the positions list.  How does that make sense?

3. How are the first 3 indices specied by the TriangleIndices list 0, 2, and 1 when the first 3 values areTriangleIndices="0 1 2"?

4. These first 3 indices are supposed to correspond to the first, third, and second points in thePositions list (Positions="-1 -1 0  1 -1 0  -1 1 0  1 1 0") but the first triangle that makes up the cube model will be composed from(1,1,0) to (0,1,0) to  (0,0,0)?  Shouldn't the first point be -1,-1,0 and the second point 1,-1,-0 and the third -1,1,0?

In trying to figure how the statements matched the code, I wasn't sure if I was missing something or if the statements were written for a different code example.  I am obviously not an M.I.T. math major but would appreciate it if someone could clarify how the statements match the code.

Thanks!

Scott

SL