Philosophy, Philosophy Of Mathematics, Zenos Paradox, Real Number System, Dilemma.
subset of positive numbers P such that (A10) (Trichotomy): exclusively either a ∈ P or −a ∈ P or a = 0. (A11) (Closure under addition): a, b ∈ P ⇒ a + b ∈ P (A12) (Closure under multiplication): a, b ∈ P ⇒ a · b ∈ P Completeness Axiom: a least upper bound of a set A is a number x such that x ≥ y