Definition An ordered field is a field F , together with a subset P ⊆ F, called the positive
set, such that
• R1: ∀x, y in P, x + y in P ;
• R2: ∀x, y in P, x · y in P;
• R3: ∀x in F, exactly one of the following must hold true:
x in P, or − x in P, or x = 0.
Also for a, b in F, We define a < b to mean b − a in P.
Question 1 (1 pt). Show that 1 in P.