ZHANG, Ruda June 04, 2022:  Add left/right inverse, matrix exponential, condition number, Frechet derivative, inverse. [667167e]
ZHANG, Ruda March 03, 2021:  Use mathcal for big O notation, to distinguish from the orthogonal group. [69caae9]
ZHANG, Ruda June 17, 2020:  Formatting. More on manifolds: integral manifold, distribution, foliation; covariant derivative along curve in submanifold; higher-order retraction. [c08c622]
ZHANG, Ruda June 12, 2020:  More on numerical analysis: Newton's method. [a6c383b]
ZHANG, Ruda May 15, 2020:  More on pseudoinverse [bc7fd0b]
ZHANG, Ruda May 02, 2020:  More on numerical analysis: Newton method; quasi-Newton methods; optimization; reference books. [67cbfe5]