Question: How do you get Maple to calculate with symbolic reals and infinity intuitively?

Hi,

I'm using Maple to carry out some calculations in Tropical algebra, which requires taking minima of real numbers and infinity.

I'm currently using symbols rather than real numbers, which is causing a problem, I have (for example) the following lines of Maple code:

> assume(0 < a)
> min(a+infinity, 2*a+infinity)
               min(a~ + infinity, 2a~ + infinity)

However, in Tropical algebra (and indeed, you could say, in 'common sense') both of the values inside the min will equal infinity, and therefore you would expect the result to equal infinity.

My question therefore is: Is there any way (i.e. any assumptions that can be placed on a, or any other tools/functions that I'm unaware of) to get Maple to give (for example):

min(a+infinity, 2*a+infinity)
               infinity

(I suppose, although I'm not sure, that this is equivalent to asking how to get Maple to give a + infinity = infinity, if you assume a is real, so answers to that question may well be helpful!)

Many thanks.