Assertion: function's number | /r/HasProperty | positive
Facets:
Source sentences:
text: Often a program must choose between two options: If the number is positive, do this; if negative, do that.
text: So the domain of count is words, and the range of count is numbers (in fact, nonnegative integers).
text: Subtraction of natural numbers (non-negative integers) can be viewed as a partial function:
text: {\displaystyle x\geq 0} because the square root function is only defined for positive numbers (assuming that we are dealing with only real numbers).