lemma
proved
phi11_lt
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IndisputableMonolith.Masses.Verification on GitHub at line 187.
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184 _ < Real.goldenRatio ^ 8 * (4.236 : ℝ) := by nlinarith
185 _ < Real.goldenRatio ^ 8 * Real.goldenRatio ^ 3 := by nlinarith
186
187private lemma phi11_lt : Constants.phi ^ (11 : ℕ) < (200 : ℝ) := by
188 rw [phi_eq_goldenRatio]
189 have h8 := Numerics.phi_pow8_lt
190 have h3 := Numerics.phi_cubed_lt
191 have hpos : (0 : ℝ) < Real.goldenRatio ^ 3 := by positivity
192 have heq : Real.goldenRatio ^ 11 = Real.goldenRatio ^ 8 * Real.goldenRatio ^ 3 := by ring_nf
193 rw [heq]
194 calc Real.goldenRatio ^ 8 * Real.goldenRatio ^ 3
195 < (46.99 : ℝ) * Real.goldenRatio ^ 3 := by nlinarith
196 _ < (46.99 : ℝ) * (4.237 : ℝ) := by nlinarith
197 _ < (200 : ℝ) := by norm_num
198
199private lemma phi17_gt : (3569 : ℝ) < Constants.phi ^ (17 : ℕ) := by
200 rw [phi_eq_goldenRatio]
201 have h8_lo := Numerics.phi_pow8_gt
202 have hφ_lo := Numerics.phi_gt_1618
203 have hpos8 : (0 : ℝ) < Real.goldenRatio ^ 8 := by positivity
204 have hpos16 : (0 : ℝ) < Real.goldenRatio ^ 8 * Real.goldenRatio ^ 8 := by positivity
205 have heq : Real.goldenRatio ^ 17 = Real.goldenRatio ^ 8 * Real.goldenRatio ^ 8 * Real.goldenRatio := by ring_nf
206 rw [heq]
207 have h16_lo : (46.97 : ℝ) * (46.97 : ℝ) < Real.goldenRatio ^ 8 * Real.goldenRatio ^ 8 :=
208 mul_lt_mul h8_lo (le_of_lt h8_lo) (by norm_num) (le_of_lt hpos8)
209 have h17_lo : (46.97 : ℝ) * (46.97 : ℝ) * (1.618 : ℝ) <
210 Real.goldenRatio ^ 8 * Real.goldenRatio ^ 8 * Real.goldenRatio :=
211 mul_lt_mul h16_lo (le_of_lt hφ_lo) (by norm_num) (le_of_lt hpos16)
212 linarith [show (3569 : ℝ) < (46.97 : ℝ) * (46.97 : ℝ) * (1.618 : ℝ) from by norm_num]
213
214private lemma phi17_lt : Constants.phi ^ (17 : ℕ) < (3574 : ℝ) := by
215 rw [phi_eq_goldenRatio]
216 have h8_hi := Numerics.phi_pow8_lt
217 have hφ_hi := Numerics.phi_lt_16185