| 0 ≤ i ⊦ binom_coef(2 * i, i) ≥ 4 ^ i / (2 * i + 1) |
binom_coef(2 * i, i) < 4 ^ i / (2 * i + 1), 0 ≤ i ⊦
Used simplifier rules: forward-le-01: ⊦ i ≤ j ∧ 0 ≤ i → 0 ≤ j; (forward) from specification int-abs%ax-01: ⊦ i ≥ j ↔ ¬ i < j; from specification int-abs