LaTeX is the language in which my lecture notes (and almost all modern mathematical papers) are written. In this blog I will use a pseudo-LaTeX notation for mathematics. So

- x_i is "x sub i",
- alpha is the Greek character α,

When I want to write in this blog some algebra or work with mathematical objects I sometimes use Mathematica's notation. So DiagonalMatrix[{1,1−alpha−beta}] is the 2x2 diagonal matrix which has 1 and 1−alpha−beta on the diagonal. Also, {{1,alpha},{1,−beta}} is the 2x2 matrix whose rows are {1,alpha} and {1,−beta}.