Sentence:  "The value of <tt><=</tt> is true if the numbers are in <WSD>monotonically</WSD> nondecreasing order; otherwise it is false." / "The value of <tt>>=</tt> is true if the numbers are in <WSD>monotonically</WSD> nonincreasing order; otherwise it is false." 
Meaning of the word marked with <WSD> tags:  In a monotonic manner, of a function that either never decreases or never increases as its independent variable increases