ZHANG, Ruda June 11, 2020:  More on multilinear operator, multivariate Taylor's formula. [35b024a]
ZHANG, Ruda June 04, 2020:  The trace operator. [86cb2bb]
ZHANG, Ruda January 21, 2020:  More on Hilbert space. [67ff8bb]
ZHANG, Ruda January 18, 2020:  Convert math-text words to text only when the math symbols are ASCII only. [e4c945c]
ZHANG, Ruda December 05, 2019:  More on manifolds, from John Marshall Lee's textbooks. [6ba9029]