theorem
proved
term proof
ladder_cascade_bound
show as:
view Lean formalization →
formal statement (Lean)
279theorem ladder_cascade_bound (a b : ℤ) :
280 Jcost (phi_ladder (a + b)) ≤
281 2 * Jcost (phi_ladder a) + 2 * Jcost (phi_ladder b) +
282 2 * Jcost (phi_ladder a) * Jcost (phi_ladder b) := by
proof body
Term-mode proof.
283 unfold phi_ladder
284 rw [← phi_power_compose]
285 exact Jcost_submult (zpow_pos PhiForcing.phi_pos a) (zpow_pos PhiForcing.phi_pos b)
286