"Any" sometimes means "all" and sometimes means "some"
An algorithm or problem is "intractable" only if it is NP-hard, that is, the asymptotic cost (or computational complexity) is believed to be worse than polynomial.
"Formula" and "expression" are not necessarily an "equation"; that latter involves an equality
Two things are "equivalent" if they are "distinguishable" with regard to some criteria. It can mean they are best "similar".
"Element" is a member of a set. And a set is "partitioned" into subsets.
"Metric" is expected to satisfy conditions. In mathematical contexts, use "measure" unless metric is intended.
Theorems
Even if there are only two or three of each in the paper, you should consider numbering key examples.
Readability
Use parentheses of appropriate size
Mathematics/digits should not be used at the start of a sentence.
ex. 7 of the runs were ~ => There were 7 successful runs ~
Avoid letting a number, symbol, or abbreviation appear at the start of the line, particularly if it is the end of a sentence. You should not let a quantity become detached from its unit.
Mathematics should have motivation. Straightforward mathematics is daunting.
Avoid unnecessary subscripts: use x and y than x_1 and x_2
Mix subscripts and superscripts with caution
Numbers
Don't mix number modes. ex. four and 32 processors => 4 and 32 processors
Fractions are only rarely used for values, and should not be used as abbreviations.
It is more logical to represent quantities to the same number of decimal places.
Guesses and approximations should be clearly indicated as such, with words such as "roughly", "nearly", "approximately", "about", "almost" or "over".
Units of Measurement
Units should be typeset in the font used in the paper for text, even when they are part of a mathmatical expression.