Actually I think this comes down to advanced set theory, of which I know a little, but not nearly as much as I would like.
Point 1:
Set theory, amoung other things, can predicate that nothing is completely "discrete" and that things need to be looked at on a continuum.
For example, I am asked "how many motorcycles do you have?" If I own a fully functional motorcycle, my answer should be "I own 1 motorcycle".
But motorcycles are generally seen as being counted in wholes, with little implicit agreement as to how a "motorcycle" is to be determined to be a "motorcycle" (you either have a motorcylce, or you do not: you are rarely asked "how many functional and how many partial motorcycles do you have").
But if the motorcyle is in parts in my garage, and I know I'm missing a couple of small parts, then, when asked "how many motorcylces do you have", I really have less then a motorcycle, but it is still perfectly acceptable to say "I have 1 motorcycle" (since saying "I have 7/8ths of a motorcycle makes little or no sense for the sake of the discussion). So in this case, motorcycles = 1 for a very low value of 1. Assuming, I buy a brand new motorcycle and keep the other in peices on the floor, and am asked this question again, I can reasonably answer either, "I have 1 motorcycle" for a very high value of "1" or I can answer "I have 2 motorcycles" for very small values of 2.
Therefor, if I have 2 complete motorcycles and most of a third, then buy 2 more complete motorcycles from a dealer, and she throws in a big box of old parts to get it them off his hands, it's not inconceivable that the two junkers put together could equal a fully functioning motorcycle. Now if I were asked, it would not be inapproprate for me to say "I had 2 motorcylces, then I bought 2 motorcycles, and now I have 5 motorcycles." In effect "2+2" =5 for extremely high values of "2".
Point 2:
From a set theory perspective even framing a question like infinity+1 > infinity makes no sense. If the set is "all things" then there can be no "thing" to add to a set of "all things". The shear act of it existing includes it in the set of "all things". The fact that it is not included in the set means it is not "a thing". So the phrase "infinity+1" is literally non-sense (e.g., [all pizzas] + [this pizza] still = [all pizzas]).
What I think IS interesting though is that though "infinity+1" as an expression is non-sense, "infinity-1" is a very concrete concept that we have all intuitively understood since before we could probably understand language.
For examle, children understand very young there are lots of people in the world, but that their mother unique and special, so of all the humans in the entire world (all things[human]) MY mother is the only one that I love. Stated another way all things[human]-1 [my mother]= 2 discrete sets:
- all things [human - my mother], and
- [my mother].
before they can even say ma-ma. I think that's neat.
Hopefully this has made some sense.
AMB