Example,

    Compute the qr factorization of a matrix.
   
    Factor the matrix `a` as `qr`, where `q` is orthonormal
    (:math:`dot( q_{:,i}, q_{:,j}) = \delta_{ij}`, the Kronecker delta) and
    `r` is upper-triangular.

Arrggghhhh... Totally. Unreadable. Why not say the columns of q are orthonormal vectors and r is upper triangular? The math tutorial should go in the notes, if anywhere. Might mention that this is a 'thin' factorization (Golub). Let me propose a rule: no math markup in the summary, ever.