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← Session 35 — ii′-6-R: Lagarias 6.1 right-tail re-proof (E-032/D-073)

#2122 assistant 2026-08-26 05:30:18.996 UTC · 985→5233 tok open ⤢
thinking (9500 chars)
Three errors: 1. **Line 155 (hnorm)**: `rw [norm_div, ← Real.sqrt_div hQpos, ...]` — the `← Real.sqrt_div` direction: Real.sqrt_div (hx : 0 ≤ x) : √(x / y) = √x / √y. The ← direction rewrites `√x / √y` → `√(x/y)` — but the goal has `‖a‖ / ‖b‖` (norms, not sqrts yet). My rw chain was wrong: I need to FIRST turn the norms into sqrts (via normSq_eq_norm_sq) THEN combine into one sqrt. The error shows the goal still has ‖↑3+↑t*I‖ / ‖↑2+↑t*I‖ and `← Real.sqrt_div` found no `√?x / √?y` pattern. Fix the chain: ``` rw [norm_div, ← Complex.normSq_eq_norm_sq, ← Complex.normSq_eq_norm_sq, hns3, hns2, ← Real.sqrt_div hQpos] ``` normSq_eq_norm_sq : normSq z = ‖z‖^2 — hmm, I want ‖z‖ = √(normSq z): ‖z‖² = normSq z ⟹ ‖z‖ = √(normSq z) (nonneg). The rewrite: `← Complex.normSq_eq_norm_sq` rewrites ‖z‖^2 → normSq z — but the goal has ‖z‖ not ‖z‖²... So I need: ‖a‖ = √(‖a‖²) = √(normSq a): ``` have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by rw [← Complex.normSq_eq_norm_sq, hns3] exact (Real.sqrt_sq (by positivity)).symm -- hmm: √(‖a‖²) = ‖a‖ ``` Cleaner: ``` have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by rw [← hns3, Complex.normSq_eq_norm_sq] exact (Real.sqrt_sq (norm_nonneg _)).symm ``` ‖a‖ = √(‖a‖²) via Real.sqrt_sq (norm_nonneg) : √(‖a‖²) = ‖a‖ — symm gives ‖a‖ = √(‖a‖²) ✓ then Complex.normSq_eq_norm_sq : ‖a‖² = normSq a... wait direction: normSq_eq_norm_sq : Complex.normSq z = ‖z‖ ^ 2 — rw [Complex.normSq_eq_norm_sq] rewrites `normSq z` → `‖z‖^2`. I have goal ‖a‖ = √(‖a‖²)... let me just: ``` have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by have h1 : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (Complex.normSq ((3 : ℝ) + t * Complex.I)) := by rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)] rw [h1, hns3] ``` Real.sqrt_sq (norm_nonneg a) : √(‖a‖ ^ 2) = ‖a‖ — after rw [Complex.normSq_eq_norm_sq]: the goal √(normSq a) = ... hmm let me redo: h1 : ‖a‖ = √(normSq a): rw [Complex.normSq_eq_norm_sq] — rewrites `normSq a` occurrences → ‖a‖^2: goal becomes ‖a‖ = √(‖a‖^2); then Real.sqrt_sq (norm_nonneg _) : √(‖a‖^2) = ‖a‖ — so `rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]` closes: goal ‖a‖ = √(normSq a) → ‖a‖ = √(‖a‖²) → ‖a‖ = ‖a‖ ✓. Then hnorm: ``` have hnorm : ‖((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)‖ = Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by rw [norm_div, hnormA, hnormB, ← Real.sqrt_div hQpos] ``` with hnormB similarly = √(4+t²). ← Real.sqrt_div hQpos: rewrites √(9+t²)/√(4+t²) → √((9+t²)/(4+t²)) ✓. 2. **Line 157 (hs1)**: `((3:ℝ) + t*I) - 1 = (2:ℝ) + t*I` — `ring` failed: the LHS is `(↑3 + ↑t * I) - 1` and the goal shows `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` — complex arithmetic: 3 + tI − 1 = (3−1) + tI = 2 + tI ✓ — ring should work over ℂ?! The goal after ring_nf suggestion... The error says "unsolved goals ⊢ -1 + ↑3 + ↑t * I = ↑t * I + ↑2" — ring normalized LHS to -1+3+tI and RHS to tI+2: -1+3 = 2 ✓ — but ring DIDN'T close it?? The message is the LEFTOVER after `ring`?? — it says ring failed, suggesting ring_nf. Weird — `ring` should handle. OH — the issue: `(3:ℝ)` is a REAL cast to ℂ, and `1` is (1:ℂ): the expression (↑3 + ↑t * I) - 1 vs (↑2 + ↑t * I)... ring over ℂ with casts — should work. But the displayed leftover: `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` — this IS a ℂ identity ring should close. Unless the `by ring` for hs1 wasn't the issue and something else is... The error at 157:74 is "unsolved goals ⊢ -1 + ↑3 + ↑t * I = ↑t * I + ↑2" — hmm, maybe `ring` partially worked and left this? Try `simp` or `ext <;> simp <;> ring`. Cleaner: prove via Complex.ext: re: 3−1 = 2 ✓ im: t = t ✓: ``` have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by rw [show ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I from by ring] ``` same thing. Try `simp [Complex.ext_iff]` then norm_num/ring: ext_iff: re = re ∧ im = im: re: (↑3 + ↑t·I − 1).re = 3−1 = 2 ✓ im: t = t ✓: ``` have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by simp [Complex.ext_iff, sub_eq_add_neg] ring ``` Hmm — let me just try `ring_nf` (the error's own suggestion) — or `field_simp; ring`... Actually the odd `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` leftover suggests ring DID normalize but the two sides' normal forms didn't unify syntactically: LHS normal: -1 + 3 + t·I = 2 + t·I; RHS: t·I + 2. These should match... unless ring treats ↑3 and ↑2 as ATOMS (casts) and ordered them differently?! LHS = -1 + ↑3 + ↑t*I: as a sum of atoms {-1, ↑3, ↑t*I}; RHS = {↑t*I, ↑2}: ring compares: -1+↑3 = 2 vs ↑2 — the atoms ↑3 and ↑2 are DIFFERENT atoms (casts of different reals!) so ring can't cancel -1+↑3 vs ↑2 UNLESS it pushes casts: ↑3 - 1 = ↑(3-1) = ↑2 — needs push_cast first! So: `push_cast; ring` or `norm_num [Complex.ext_iff]`. Use: ``` have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by push_cast ring ``` push_cast normalizes ↑(3) − 1 → ↑(3−1) → ↑2 ✓ then ring ✓. (Session-035 banked: "push_cast EM conclusions before linear_combination" — same cast issue ✓.) 3. **Line 167: `Real.sqrt_pow` unknown** — wrong name. The correct name in this Mathlib: `Real.sqrt_pow` doesn't exist; alternatives: `Real.sqrt_pow` vs `Real.sq_sqrt` vs... For (√x)^n = √(x^n): `Real.sqrt_pow`?? — unknown. Search: there's `Real.sqrt_sq`, `Real.sq_sqrt`, `Real.sqrt_mul_self`, `Real.pow_sqrt_two_add`... The power identity: (√x)^n = x^(n/2)... Let me think of an alternate route: avoid sqrt_pow: (√Q)^n ≤ e^{5/2} ⟺ ((√Q)^n)² ≤ e⁵ ⟸ (√Q)^{2n} = Qⁿ ≤ e⁵: ((√Q)^n)² = (Q^{1/2... — ((√Q)^n)² = ((√Q)²)ⁿ = Qⁿ (via ← pow_mul: (a^n)² = a^{2n}... ((√Q)^n)² = (√Q)^{n·2} = ((√Q)²)ⁿ = Qⁿ by Real.sq_sqrt hQpos : √(Q)² = Q — (√Q)² = Q ✓ Real.sq_sqrt (hx : 0 ≤ x) : (√x)^2 = x ✓). So: ``` have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 ≤ Real.exp 5 := by rw [← pow_mul, Real.sq_sqrt hQpos] calc ((9 + t ^ 2) / (4 + t ^ 2)) ^ n ≤ Real.exp 5 := hQn _ = Real.exp 5 := rfl -- from x² ≤ e⁵ to x ≤ e^{5/2} for x ≥ 0 have hx : (0 : ℝ) ≤ (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n := by positivity have h6 : Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) ≤ Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5 rw [Real.sqrt_sq hx, Real.sqrt_exp] at h6 exact h6 ``` ← pow_mul: (a^n)^2 = a^{n·2}; then Real.sq_sqrt hQpos : (√Q)^2 = Q — wait after ← pow_mul the term is (√Q)^{n·2} = ((√Q)^2)^n?? pow_mul : a^(m·n) = (a^m)^n — (a^n)^2 = a^(n·2) via ← pow_mul ✓ then a^(n·2) = (a²)^n via pow_mul m n : a^(m*n) = (a^m)^n — hmm: √Q^(n·2): rw [pow_mul] gives (√Q^n)^2 ← no. Let me redo: goal ((√Q)^n)^2 ≤ e⁵. `rw [← pow_mul]`: ← pow_mul rewrites a^(m*n) → (a^m)^n — I want (√Q^n)^2 → √Q^(n*2): that's pow_mul DIRECTION (a^(m*n) = (a^m)^n reversed: (a^m)^n = a^(m*n) is ← pow_mul; I want (a^n)^2 → a^(n*2): also ← pow_mul with m := n, n := 2 ✓): rw [← pow_mul] at goal: ((√Q)^n)^2 = (√Q)^(n*2) ✓. Then (√Q)^(n*2) = ((√Q)^2)^n via pow_mul (√Q) n 2 : (√Q)^(n*2) = ((√Q)^n)^2 — no that's backward again. pow_mul a m n : a ^ (m * n) = (a ^ m) ^ n — so (√Q)^(n*2) = ((√Q)^n)^2 ✓ (back where we were) OR ((√Q)^(2*n)) = ((√Q)^2)^n ✓. So: rw [← pow_mul] → (√Q)^(n*2); rw [mul_comm n 2, pow_mul] → ((√Q)^2)^n; rw [Real.sq_sqrt hQpos] → Q^n ✓. Simpler: use `Real.rpow`... no. Alternative clean route: ``` have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 ≤ Real.exp 5 := by have e : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 = (((9 + t ^ 2) / (4 + t ^ 2))) ^ n := by rw [← pow_mul, mul_comm n 2, pow_mul, Real.sq_sqrt hQpos] rw [e] exact hQn ``` Then the sqrt-of-squares step above (h6). Even simpler for the final step: `Real.sqrt_le_sqrt hQn` route needs sqrt_pow to connect (√Q)^n with √(Q^n)... — hmm the actual lemma name for (√x)^n = √(x^n): `Real.sqrt_pow`?? unknown constant. Maybe `Real.sqrt_pow_of_nonneg`? or the form via `Real.sqrt_eq_rpow` + rpow... Let me just use the x²-comparison route (h5/h6) — self-contained, no sqrt_pow needed. The h6 chain: ``` have h6 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by have hx0 : (0 : ℝ) ≤ Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := Real.sqrt_nonneg _ have hx : (0 : ℝ) ≤ (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n := pow_nonneg hx0 n have h8 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n = Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) := by rw [Real.sqrt_sq hx] rw [h8] calc Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) ≤ Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5 _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp] ``` Real.sqrt_sq (hx : 0 ≤ x) : √(x ^ 2) = x ✓ — rw [Real.sqrt_sq hx] at h8's goal: √(x²) → x ✓ so h8 : y = √(y²) where y = (√Q)^n: rw [Real.sqrt_sq hx] rewrites √(y²) → y: goal y = y ✓ — hmm rw on h8's statement `y = √(y^2)`: rewriting √(y²)→y turns RHS into y: y = y ✓ closed by rfl ✓. That's clean. Apply the three fixes: 1. hnormA/hnormB approach for hnorm. 2. hs1 via push_cast + ring. 3. the h4 sqrt-chain via h5/h6.
Three fixes: the norm-to-sqrt chain needs `Real.sqrt_sq`, the ℂ subtraction needs `push_cast` before `ring`, and `Real.sqrt_pow` doesn't exist in this Mathlib — using a squares-comparison instead.
tool: Edit
input
{
  "file_path": "D:\\Python\\Quantum\\research\\lean\\NguyenRH1\\NguyenRH1\\LiDogLeg.lean",
  "old_string": "    have hns3 : Complex.normSq ((3 : \u211d) + t * Complex.I) = 9 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hns2 : Complex.normSq ((2 : \u211d) + t * Complex.I) = 4 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hnorm : \u2016((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)\u2016 =\n        Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by\n      rw [norm_div, \u2190 Real.sqrt_div hQpos, \u2190 Complex.normSq_eq_norm_sq,\n        \u2190 Complex.normSq_eq_norm_sq, hns3, hns2]\n    have hs1 : ((3 : \u211d) + t * Complex.I) - 1 = (2 : \u211d) + t * Complex.I := by ring\n    unfold kFun\n    rw [hs1]\n    calc \u2016(((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)) ^ n - 1\u2016\n        \u2264 \u2016(((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)) ^ n\u2016 + \u2016(1 : \u2102)\u2016 :=\n          norm_sub_le _ _\n      _ = (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n + 1 := by\n          rw [norm_pow, hnorm, norm_one]\n      _ \u2264 Real.exp (5 / 2) + 1 := by\n          have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n \u2264 Real.exp (5 / 2) := by\n            rw [Real.sqrt_pow]\n            calc Real.sqrt (((9 + t ^ 2) / (4 + t ^ 2)) ^ n)\n                \u2264 Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt hQn\n              _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp]\n          linarith [h4]",
  "new_string": "    have hns3 : Complex.normSq ((3 : \u211d) + t * Complex.I) = 9 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hns2 : Complex.normSq ((2 : \u211d) + t * Complex.I) = 4 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hnormA : \u2016((3 : \u211d) + t * Complex.I)\u2016 = Real.sqrt (9 + t ^ 2) := by\n      have h1 : \u2016((3 : \u211d) + t * Complex.I)\u2016 =\n          Real.sqrt (Complex.normSq ((3 : \u211d) + t * Complex.I)) := by\n        rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]\n      rw [h1, hns3]\n    have hnormB : \u2016((2 : \u211d) + t * Complex.I)\u2016 = Real.sqrt (4 + t ^ 2) := by\n      have h1 : \u2016((2 : \u211d) + t * Complex.I)\u2016 =\n          Real.sqrt (Complex.normSq ((2 : \u211d) + t * Complex.I)) := by\n        rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]\n      rw [h1, hns2]\n    have hnorm : \u2016((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)\u2016 =\n        Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by\n      rw [norm_div, hnormA, hnormB, \u2190 Real.sqrt_div hQpos]\n    have hs1 : ((3 : \u211d) + t * Complex.I) - 1 = (2 : \u211d) + t * Complex.I := by\n      push_cast\n      ring\n    unfold kFun\n    rw [hs1]\n    calc \u2016(((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)) ^ n - 1\u2016\n        \u2264 \u2016(((3 : \u211d) + t * Complex.I) / ((2 : \u211d) + t * Complex.I)) ^ n\u2016 + \u2016(1 : \u2102)\u2016 :=\n          norm_sub_le _ _\n      _ = (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n + 1 := by\n          rw [norm_pow, hnorm, norm_one]\n      _ \u2264 Real.exp (5 / 2) + 1 := by\n          have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n \u2264 Real.exp (5 / 2) := by\n            have hx0 : (0 : \u211d) \u2264 Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) :=\n              Real.sqrt_nonneg _\n            have hx : (0 : \u211d) \u2264 (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n :=\n              pow_nonneg hx0 n\n            have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 \u2264 Real.exp 5 := by\n              have e : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 =\n                  ((9 + t ^ 2) / (4 + t ^ 2)) ^ n := by\n                rw [\u2190 pow_mul, mul_comm n 2, pow_mul, Real.sq_sqrt hQpos]\n              rw [e]\n              exact hQn\n            have h8 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n =\n                Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) := by\n              rw [Real.sqrt_sq hx]\n            rw [h8]\n            calc Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2)\n                \u2264 Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5\n              _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp]\n          linarith [h4]"
}
raw content_json (database row)
[{"type":"thinking","thinking":"Three errors:\n\n1. **Line 155 (hnorm)**: `rw [norm_div, ← Real.sqrt_div hQpos, ...]` — the `← Real.sqrt_div` direction: Real.sqrt_div (hx : 0 ≤ x) : √(x / y) = √x / √y. The ← direction rewrites `√x / √y` → `√(x/y)` — but the goal has `‖a‖ / ‖b‖` (norms, not sqrts yet). My rw chain was wrong: I need to FIRST turn the norms into sqrts (via normSq_eq_norm_sq) THEN combine into one sqrt. The error shows the goal still has ‖↑3+↑t*I‖ / ‖↑2+↑t*I‖ and `← Real.sqrt_div` found no `√?x / √?y` pattern. Fix the chain: \n```\n      rw [norm_div, ← Complex.normSq_eq_norm_sq, ← Complex.normSq_eq_norm_sq, hns3, hns2,\n        ← Real.sqrt_div hQpos]\n```\nnormSq_eq_norm_sq : normSq z = ‖z‖^2 — hmm, I want ‖z‖ = √(normSq z): ‖z‖² = normSq z ⟹ ‖z‖ = √(normSq z) (nonneg). The rewrite: `← Complex.normSq_eq_norm_sq` rewrites ‖z‖^2 → normSq z — but the goal has ‖z‖ not ‖z‖²... So I need: ‖a‖ = √(‖a‖²) = √(normSq a): \n```\n    have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by\n      rw [← Complex.normSq_eq_norm_sq, hns3]\n      exact (Real.sqrt_sq (by positivity)).symm  -- hmm: √(‖a‖²) = ‖a‖\n```\nCleaner:\n```\n    have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by\n      rw [← hns3, Complex.normSq_eq_norm_sq]\n      exact (Real.sqrt_sq (norm_nonneg _)).symm\n```\n‖a‖ = √(‖a‖²) via Real.sqrt_sq (norm_nonneg) : √(‖a‖²) = ‖a‖ — symm gives ‖a‖ = √(‖a‖²) ✓ then Complex.normSq_eq_norm_sq : ‖a‖² = normSq a... wait direction: normSq_eq_norm_sq : Complex.normSq z = ‖z‖ ^ 2 — rw [Complex.normSq_eq_norm_sq] rewrites `normSq z` → `‖z‖^2`. I have goal ‖a‖ = √(‖a‖²)... let me just:\n```\n    have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by\n      have h1 : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (Complex.normSq ((3 : ℝ) + t * Complex.I)) := by\n        rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]\n      rw [h1, hns3]\n```\nReal.sqrt_sq (norm_nonneg a) : √(‖a‖ ^ 2) = ‖a‖ — after rw [Complex.normSq_eq_norm_sq]: the goal √(normSq a) = ... hmm let me redo: h1 : ‖a‖ = √(normSq a): rw [Complex.normSq_eq_norm_sq] — rewrites `normSq a` occurrences → ‖a‖^2: goal becomes ‖a‖ = √(‖a‖^2); then Real.sqrt_sq (norm_nonneg _) : √(‖a‖^2) = ‖a‖ — so `rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]` closes: goal ‖a‖ = √(normSq a) → ‖a‖ = √(‖a‖²) → ‖a‖ = ‖a‖ ✓.\n\nThen hnorm: \n```\n    have hnorm : ‖((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)‖ =\n        Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by\n      rw [norm_div, hnormA, hnormB, ← Real.sqrt_div hQpos]\n```\nwith hnormB similarly = √(4+t²). ← Real.sqrt_div hQpos: rewrites √(9+t²)/√(4+t²) → √((9+t²)/(4+t²)) ✓.\n\n2. **Line 157 (hs1)**: `((3:ℝ) + t*I) - 1 = (2:ℝ) + t*I` — `ring` failed: the LHS is `(↑3 + ↑t * I) - 1` and the goal shows `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` — complex arithmetic: 3 + tI − 1 = (3−1) + tI = 2 + tI ✓ — ring should work over ℂ?! The goal after ring_nf suggestion... The error says \"unsolved goals ⊢ -1 + ↑3 + ↑t * I = ↑t * I + ↑2\" — ring normalized LHS to -1+3+tI and RHS to tI+2: -1+3 = 2 ✓ — but ring DIDN'T close it?? The message is the LEFTOVER after `ring`?? — it says ring failed, suggesting ring_nf. Weird — `ring` should handle. OH — the issue: `(3:ℝ)` is a REAL cast to ℂ, and `1` is (1:ℂ): the expression (↑3 + ↑t * I) - 1 vs (↑2 + ↑t * I)... ring over ℂ with casts — should work. But the displayed leftover: `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` — this IS a ℂ identity ring should close. Unless the `by ring` for hs1 wasn't the issue and something else is... The error at 157:74 is \"unsolved goals ⊢ -1 + ↑3 + ↑t * I = ↑t * I + ↑2\" — hmm, maybe `ring` partially worked and left this? Try `simp` or `ext <;> simp <;> ring`. Cleaner: prove via Complex.ext: re: 3−1 = 2 ✓ im: t = t ✓:\n```\n    have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by\n      rw [show ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I from by ring]\n```\nsame thing. Try `simp [Complex.ext_iff]` then norm_num/ring: ext_iff: re = re ∧ im = im: re: (↑3 + ↑t·I − 1).re = 3−1 = 2 ✓ im: t = t ✓: \n```\n    have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by\n      simp [Complex.ext_iff, sub_eq_add_neg]\n      ring\n```\nHmm — let me just try `ring_nf` (the error's own suggestion) — or `field_simp; ring`... Actually the odd `-1 + ↑3 + ↑t * I = ↑t * I + ↑2` leftover suggests ring DID normalize but the two sides' normal forms didn't unify syntactically: LHS normal: -1 + 3 + t·I = 2 + t·I; RHS: t·I + 2. These should match... unless ring treats ↑3 and ↑2 as ATOMS (casts) and ordered them differently?! LHS = -1 + ↑3 + ↑t*I: as a sum of atoms {-1, ↑3, ↑t*I}; RHS = {↑t*I, ↑2}: ring compares: -1+↑3 = 2 vs ↑2 — the atoms ↑3 and ↑2 are DIFFERENT atoms (casts of different reals!) so ring can't cancel -1+↑3 vs ↑2 UNLESS it pushes casts: ↑3 - 1 = ↑(3-1) = ↑2 — needs push_cast first! So: `push_cast; ring` or `norm_num [Complex.ext_iff]`. Use:\n```\n    have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by\n      push_cast\n      ring\n```\npush_cast normalizes ↑(3) − 1 → ↑(3−1) → ↑2 ✓ then ring ✓. (Session-035 banked: \"push_cast EM conclusions before linear_combination\" — same cast issue ✓.)\n\n3. **Line 167: `Real.sqrt_pow` unknown** — wrong name. The correct name in this Mathlib: `Real.sqrt_pow` doesn't exist; alternatives: `Real.sqrt_pow` vs `Real.sq_sqrt` vs... For (√x)^n = √(x^n): `Real.sqrt_pow`?? — unknown. Search: there's `Real.sqrt_sq`, `Real.sq_sqrt`, `Real.sqrt_mul_self`, `Real.pow_sqrt_two_add`... The power identity: (√x)^n = x^(n/2)... Let me think of an alternate route: avoid sqrt_pow: \n(√Q)^n ≤ e^{5/2} ⟺ ((√Q)^n)² ≤ e⁵ ⟸ (√Q)^{2n} = Qⁿ ≤ e⁵: ((√Q)^n)² = (Q^{1/2... — ((√Q)^n)² = ((√Q)²)ⁿ = Qⁿ (via ← pow_mul: (a^n)² = a^{2n}... ((√Q)^n)² = (√Q)^{n·2} = ((√Q)²)ⁿ = Qⁿ by Real.sq_sqrt hQpos : √(Q)² = Q — (√Q)² = Q ✓ Real.sq_sqrt (hx : 0 ≤ x) : (√x)^2 = x ✓). So:\n```\n          have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by\n            have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 ≤ Real.exp 5 := by\n              rw [← pow_mul, Real.sq_sqrt hQpos]\n              calc ((9 + t ^ 2) / (4 + t ^ 2)) ^ n ≤ Real.exp 5 := hQn\n                _ = Real.exp 5 := rfl\n            -- from x² ≤ e⁵ to x ≤ e^{5/2} for x ≥ 0\n            have hx : (0 : ℝ) ≤ (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n := by positivity\n            have h6 : Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) ≤\n                Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5\n            rw [Real.sqrt_sq hx, Real.sqrt_exp] at h6\n            exact h6\n```\n← pow_mul: (a^n)^2 = a^{n·2}; then Real.sq_sqrt hQpos : (√Q)^2 = Q — wait after ← pow_mul the term is (√Q)^{n·2} = ((√Q)^2)^n?? pow_mul : a^(m·n) = (a^m)^n — (a^n)^2 = a^(n·2) via ← pow_mul ✓ then a^(n·2) = (a²)^n via pow_mul m n : a^(m*n) = (a^m)^n — hmm: √Q^(n·2): rw [pow_mul] gives (√Q^n)^2 ← no. Let me redo: goal ((√Q)^n)^2 ≤ e⁵. `rw [← pow_mul]`: ← pow_mul rewrites a^(m*n) → (a^m)^n — I want (√Q^n)^2 → √Q^(n*2): that's pow_mul DIRECTION (a^(m*n) = (a^m)^n reversed: (a^m)^n = a^(m*n) is ← pow_mul; I want (a^n)^2 → a^(n*2): also ← pow_mul with m := n, n := 2 ✓): rw [← pow_mul] at goal: ((√Q)^n)^2 = (√Q)^(n*2) ✓. Then (√Q)^(n*2) = ((√Q)^2)^n via pow_mul (√Q) n 2 : (√Q)^(n*2) = ((√Q)^n)^2 — no that's backward again. pow_mul a m n : a ^ (m * n) = (a ^ m) ^ n — so (√Q)^(n*2) = ((√Q)^n)^2 ✓ (back where we were) OR ((√Q)^(2*n)) = ((√Q)^2)^n ✓. So: rw [← pow_mul] → (√Q)^(n*2); rw [mul_comm n 2, pow_mul] → ((√Q)^2)^n; rw [Real.sq_sqrt hQpos] → Q^n ✓. \n\nSimpler: use `Real.rpow`... no. Alternative clean route: \n```\n            have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 ≤ Real.exp 5 := by\n              have e : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 =\n                  (((9 + t ^ 2) / (4 + t ^ 2))) ^ n := by\n                rw [← pow_mul, mul_comm n 2, pow_mul, Real.sq_sqrt hQpos]\n              rw [e]\n              exact hQn\n```\nThen the sqrt-of-squares step above (h6).\n\nEven simpler for the final step: `Real.sqrt_le_sqrt hQn` route needs sqrt_pow to connect (√Q)^n with √(Q^n)... — hmm the actual lemma name for (√x)^n = √(x^n): `Real.sqrt_pow`?? unknown constant. Maybe `Real.sqrt_pow_of_nonneg`? or the form via `Real.sqrt_eq_rpow` + rpow... Let me just use the x²-comparison route (h5/h6) — self-contained, no sqrt_pow needed. The h6 chain:\n```\n            have h6 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by\n              have hx0 : (0 : ℝ) ≤ Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := Real.sqrt_nonneg _\n              have hx : (0 : ℝ) ≤ (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n := pow_nonneg hx0 n\n              have h8 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n =\n                  Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) := by\n                rw [Real.sqrt_sq hx]\n              rw [h8]\n              calc Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2)\n                  ≤ Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5\n                _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp]\n```\nReal.sqrt_sq (hx : 0 ≤ x) : √(x ^ 2) = x ✓ — rw [Real.sqrt_sq hx] at h8's goal: √(x²) → x ✓ so h8 : y = √(y²) where y = (√Q)^n: rw [Real.sqrt_sq hx] rewrites √(y²) → y: goal y = y ✓ — hmm rw on h8's statement `y = √(y^2)`: rewriting √(y²)→y turns RHS into y: y = y ✓ closed by rfl ✓.\n\nThat's clean. Apply the three fixes:\n1. hnormA/hnormB approach for hnorm.\n2. hs1 via push_cast + ring.\n3. the h4 sqrt-chain via h5/h6.","signature":""},{"type":"text","text":"Three fixes: the norm-to-sqrt chain needs `Real.sqrt_sq`, the ℂ subtraction needs `push_cast` before `ring`, and `Real.sqrt_pow` doesn't exist in this Mathlib — using a squares-comparison instead."},{"type":"tool_use","id":"Edit_206","name":"Edit","input":{"file_path":"D:\\Python\\Quantum\\research\\lean\\NguyenRH1\\NguyenRH1\\LiDogLeg.lean","old_string":"    have hns3 : Complex.normSq ((3 : ℝ) + t * Complex.I) = 9 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hns2 : Complex.normSq ((2 : ℝ) + t * Complex.I) = 4 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hnorm : ‖((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)‖ =\n        Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by\n      rw [norm_div, ← Real.sqrt_div hQpos, ← Complex.normSq_eq_norm_sq,\n        ← Complex.normSq_eq_norm_sq, hns3, hns2]\n    have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by ring\n    unfold kFun\n    rw [hs1]\n    calc ‖(((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)) ^ n - 1‖\n        ≤ ‖(((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)) ^ n‖ + ‖(1 : ℂ)‖ :=\n          norm_sub_le _ _\n      _ = (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n + 1 := by\n          rw [norm_pow, hnorm, norm_one]\n      _ ≤ Real.exp (5 / 2) + 1 := by\n          have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by\n            rw [Real.sqrt_pow]\n            calc Real.sqrt (((9 + t ^ 2) / (4 + t ^ 2)) ^ n)\n                ≤ Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt hQn\n              _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp]\n          linarith [h4]","new_string":"    have hns3 : Complex.normSq ((3 : ℝ) + t * Complex.I) = 9 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hns2 : Complex.normSq ((2 : ℝ) + t * Complex.I) = 4 + t ^ 2 := by\n      simp [Complex.normSq_apply]\n      ring\n    have hnormA : ‖((3 : ℝ) + t * Complex.I)‖ = Real.sqrt (9 + t ^ 2) := by\n      have h1 : ‖((3 : ℝ) + t * Complex.I)‖ =\n          Real.sqrt (Complex.normSq ((3 : ℝ) + t * Complex.I)) := by\n        rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]\n      rw [h1, hns3]\n    have hnormB : ‖((2 : ℝ) + t * Complex.I)‖ = Real.sqrt (4 + t ^ 2) := by\n      have h1 : ‖((2 : ℝ) + t * Complex.I)‖ =\n          Real.sqrt (Complex.normSq ((2 : ℝ) + t * Complex.I)) := by\n        rw [Complex.normSq_eq_norm_sq, Real.sqrt_sq (norm_nonneg _)]\n      rw [h1, hns2]\n    have hnorm : ‖((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)‖ =\n        Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) := by\n      rw [norm_div, hnormA, hnormB, ← Real.sqrt_div hQpos]\n    have hs1 : ((3 : ℝ) + t * Complex.I) - 1 = (2 : ℝ) + t * Complex.I := by\n      push_cast\n      ring\n    unfold kFun\n    rw [hs1]\n    calc ‖(((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)) ^ n - 1‖\n        ≤ ‖(((3 : ℝ) + t * Complex.I) / ((2 : ℝ) + t * Complex.I)) ^ n‖ + ‖(1 : ℂ)‖ :=\n          norm_sub_le _ _\n      _ = (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n + 1 := by\n          rw [norm_pow, hnorm, norm_one]\n      _ ≤ Real.exp (5 / 2) + 1 := by\n          have h4 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n ≤ Real.exp (5 / 2) := by\n            have hx0 : (0 : ℝ) ≤ Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2)) :=\n              Real.sqrt_nonneg _\n            have hx : (0 : ℝ) ≤ (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n :=\n              pow_nonneg hx0 n\n            have h5 : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 ≤ Real.exp 5 := by\n              have e : ((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2 =\n                  ((9 + t ^ 2) / (4 + t ^ 2)) ^ n := by\n                rw [← pow_mul, mul_comm n 2, pow_mul, Real.sq_sqrt hQpos]\n              rw [e]\n              exact hQn\n            have h8 : (Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n =\n                Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2) := by\n              rw [Real.sqrt_sq hx]\n            rw [h8]\n            calc Real.sqrt (((Real.sqrt ((9 + t ^ 2) / (4 + t ^ 2))) ^ n) ^ 2)\n                ≤ Real.sqrt (Real.exp 5) := Real.sqrt_le_sqrt h5\n              _ = Real.exp (5 / 2) := by rw [Real.sqrt_exp]\n          linarith [h4]"},"extra_content":null}]