theorem
proved
term proof
rsExists_iff_one
show as:
view Lean formalization →
formal statement (Lean)
40theorem rsExists_iff_one {x : ℝ} (hx : 0 < x) :
41 RSExists x ↔ x = 1 := by
proof body
Term-mode proof.
42 unfold RSExists
43 constructor
44 · intro h
45 by_contra hne
46 exact absurd h (ne_of_gt (Jcost_pos_of_ne_one x hx hne))
47 · rintro rfl
48 exact Jcost_unit0
49
50/-- Non-existence costs more than zero. -/