TITLE: Nonnegative vs non-negative
QUESTION [15 upvotes]: When you write about integers that are not negative, do you write "non-negative integers" or "nonnegative integers" in papers in US English?
EDIT: 
In https://ieeecs-media.computer.org/media/conferences/cpstemplates/8.5x11x2/instruct8.5x11x2.pdf we see

The prefix “non” is not a word; it should be joined to the word it modifies, usually without a hyphen.

The really diffuse word above is "usually". :-)

REPLY [4 votes]: The American Mathematical Society Style Guide states on page 92, section 12.7.5.3

Do not hyphenate words formed with the prefixes ... “non-” ...

Similarly, the Society for Industrial and Applied Mathematics Style Manual states on page 40, section 3.6.6

Don’t hyphenate  words formed with the prefixes ... "non-" ...

Both guides refer to The Chicago Manual of Style for exceptions.