pith. machine review for the scientific record. sign in
theorem proved tactic proof

phi_gt_one

show as:
view Lean formalization →

No prose has been written for this declaration yet. The Lean source and graph data below render without it.

generate prose now

formal statement (Lean)

  28theorem phi_gt_one : phi > 1 := by

proof body

Tactic-mode proof.

  29  unfold phi
  30  have h5 : Real.sqrt 5 > 1 := by
  31    rw [show (1 : ℝ) = Real.sqrt 1 from (Real.sqrt_one).symm]
  32    exact Real.sqrt_lt_sqrt (by norm_num) (by norm_num)
  33  linarith
  34
  35/-- A phi-bit: the amount of information in a binary choice
  36    with phi-weighted branches. -/

depends on (9)

Lean names referenced from this declaration's body.