Agree with jdporter above, not aware of any coordinate system where 7.133 > 7.23.

I think maybe the varying degrees of accuracy are causing confusion? 7.133 is accurate to the thousandths place, where 7.23 is only accurate to the hundredths place. Does this make it easier to understand:

7.23 = 7.230

7.230 > 7.133

UPDATE:A-ha, so this isn't coordinate space, rather Tk indices, see Re: Find range in coordinates array below.