Bob and Sarah are a physicist and chemist, respectively. They should have known better than to send us mad libs for an RSVP card.
Translation: On July 23rd, Bob and Sarah will finally be elements of the set of unordered pairs of people. Kyle is very (the official sequence ID of the "happy numbers") for them, and wishes them an uncountable infinity of happiness and that they should be an ideal example of the wedding ring together. Therefore, 1 will, with less than 1 percent conformance with the null hypothesis, attend and look forward to seeing the undefined (as bride/groom is indivisible) in their Klein bottle dress/suit.
3 imaginary people will attend with greater than 2 sigma (2 standard deviations away from a normal distribution of error) confidence, and hopes that the couple plays Crab Canon, a piece by Bach structured like a closely related non-orientable manifold, the Mobius strip.
Nobody requests the London Broil, 1 +/- 0.5 would like the Chicken Piccata, and 0 will have the Mushroom Steak. A strictly speaking undefined but we're physicists so fuck it, it's zero number of people are positive that they cannot attend, because of undefinite orders from the nonexistent fourth floor of the physics and chemistry building they spend so much time in.