Interestingly, it would appear that monotonically increasing in general means "strictly increasing": http://mathworld.wolfram.com/MonotoneIncreasing.htm http://

Interestingly, it would appear that monotonically increasing in general means "strictly increasing": http://mathworld.wolfram.com/MonotoneIncreasing.htm http://mathworld.wolfram.com/MonotoneIncreasing.htm It only means non-decreasing in the context of a monotonic function, where the definition, I believe, is that the derivative of the function is never <0.