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← Session 21 — Tier ii′ planning + launch: close SfBoundProp in Lean (D-064)

#974 assistant 2026-08-21 22:14:36.300 UTC · 1829→4356 tok open ⤢
thinking (10715 chars)
I see the HDiv error source: in `hnum.div hden (pow_ne_zero _ hw1)` — `hnum.div` — ContinuousAt.div — the dot-projection: hnum : ContinuousAt (fun w => Acoeff n i) w — `.div hden (pow_ne_zero _ hw1)` — ContinuousAt.div (hf) (hg) (hz : g x ≠ 0) : ContinuousAt (f / g) x — the result (f/g) — Pi division: HDiv (ℂ → ?) — the ERROR `HDiv ℂ ℂ (ℂ → ?m.5)` — hmm — ContinuousAt.div's result: `ContinuousAt (f / g) x` where (f / g) : α → β with pointwise division — instance `Pi.div` — the division f/g of FUNCTIONS — the goal (after `exact`) is the hterm statement `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — Lean must unify `(fun w => Acoeff n i) / (fun w => (w−1)^i)` with `fun w => Acoeff n i / (w−1)^i` — Pi.div_apply defeq ✓ — but the ERROR is at 229:46 which is... line 229 = `exact hnum.div hden (pow_ne_zero _ hw1)`?? — let me count: 229 is `have hden : ContinuousAt (fun w => (w - 1) ^ i) w :=` region or the `(continuousAt_id.sub continuousAt_const).pow _` line (229:46 is the `.pow _` position). `.pow _` — ContinuousAt.pow (h) (n) — with `_` — the HDiv error at that position?? no... Actually — the errors at 229:46 and 237:48 mention `HDiv ℂ ℂ (ℂ → ?m.209 s)` — `?m.209 s` — a function applied to s! In the induction case: `ContinuousAt.add hs (hterm a)` — hs : ContinuousAt (∑ i ∈ s, ...) — wait — ContinuousAt.add (hf) (hg) : ContinuousAt (f + g) x — the goal (after rw [Finset.sum_insert has]) is `ContinuousAt (∑ i ∈ insert a s, ...) w` which rw turned into `ContinuousAt (∑ i ∈ s, ... + Acoeff n a / (w−1)^a) w`?? — Finset.sum_insert : ∑ i ∈ insert a s, f i = f a + ∑ i ∈ s, f i ✓ — so goal: `ContinuousAt (Acoeff n a / (w−1)^a + ∑ i ∈ s, Acoeff n i / (w−1)^i) w` — ContinuousAt.add hs (hterm a) : ContinuousAt ((∑-function) + (term-function)) — via Pi.add — matches the goal up to add order ✓ should work... The HDiv error `ℂ → ?m.209 s` — something is divided by a FUNCTION. Where? `Acoeff n i / (w - 1) ^ i` — WAIT. I bet the issue is `(w - 1) ^ i` — if `i` here is NOT the natural number exponent but got elaborated as... no. Hmm, `Acoeff n i / (w - 1) ^ i` — Lean parses this as `HDiv.hDiv (Acoeff n i) ((w - 1) ^ i)` — HDiv ℂ ℂ — fine... Unless — `Acoeff n i` is not ℂ! Acoeff def: `Acoeff (n i : ℕ) : ℂ := iteratedDeriv (n + 1 - i) ... 1 / Nat.factorial (n + 1 - i)` — hmm wait — the elaboration of `Acoeff n i` requires Acoeff to be fully elaborated — if Acoeff's def has an ERROR (line 178/188 simp failures are in DIFFERENT lemmas — Gprim_differentiableAt/deriv_Gprim), Acoeff itself might be fine... The errors at 178/188 are `unfold Gprim` + `apply DifferentiableAt.sum` / `rw [deriv_sum ...]` — those are the NEXT lemmas. Acoeff compiled (no error at 162 now after Nat.factorial fix — the error list no longer shows 162). So the HDiv error is genuinely in tail_continuousAt. `HDiv ℂ ℂ (ℂ → ?m.209 s)` — the `?m.209 s` — an application of a metavariable to s — in the `insert` case, `rename_i a s` renamed s — the goal after `rw [Finset.sum_insert has]`: `ContinuousAt (Acoeff n a / (w - 1) ^ a + ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — and `ContinuousAt.add hs (hterm a)` — ContinuousAt.add : ContinuousAt (f + g) x with (f + g) via Pi.add — Pi.add's instance HDiv?? no, Pi.add is HAdd. The HDiv error — hmm — `ContinuousAt.add` might not exist! Check: `ContinuousAt.add (hf : ContinuousAt f x) (hg : ContinuousAt g x) : ContinuousAt (f + g) x` ✓ exists I'm sure. OK let me just look at line numbers precisely: 229:46 and 237:48. Line 229 in the current file — the `have hden` line or `.pow _`. 237 = `exact ContinuousAt.add hs (hterm a)`. The HDiv error at 237:48 = the `hterm a` position — hterm a : ContinuousAt (fun w => Acoeff n a / (w - 1) ^ a) w — the HDiv ℂ ℂ (ℂ → ?m.209 s) — `?m.209 s` — s is the Finset! `Acoeff n i / (w - 1) ^ i` — WAIT. I see it: in hterm's statement I wrote `fun w => Acoeff n i / (w - 1) ^ i` — Lean might parse `Acoeff n i / (w - 1) ^ i` as `(Acoeff n i / (w - 1)) ^ i`?? — no, ^ binds tighter... UNLESS the elaboration made `(w - 1) ^ i` into `HPow.hPow (w-1) i` ✓ fine. Hold on — `?m.209 s` — s applied — the sum `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` — the summand is a FUNCTION of i (with w FIXED — this is a sum over ℂ values, not functions!). The sum `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` is a COMPLEX NUMBER (sum of complex terms) ✓ — the ContinuousAt is of a CONSTANT function?? NO — tail_continuousAt's statement: `ContinuousAt (∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w` — the sum is a fixed complex number and ContinuousAt of a constant — THAT'S NOT WHAT I WANT! The tail sum as a function of w: I need `fun w => ∑ i, Acoeff n i / (w - 1) ^ i`!! In rectInt_deriv_eq_zero's hGc hypothesis I need ContinuousAt (deriv (Gprim n)) s — with deriv_Gprim: deriv (Gprim n) w = ∑ i, Acoeff n i / (w - 1) ^ i — as functions of w. But tail_continuousAt's statement lacks the `fun w =>`!! The goal `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — the sum over i of (Acoeff n i / (w−1)^i) — this IS a function of w implicitly?? NO — `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` with w : ℂ a VARIABLE — the sum's VALUE depends on w — so the expression IS a function of w (the lambda is implicit in the proposition). ContinuousAt (expr-involving-w) w — Lean elaborates ContinuousAt f w with f := fun w => expr ✓ — that's how it works (the `this : ∀ s : Finset ℕ, ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — with w free — Lean generalizes f := fun w => ∑ i ∈ s, ... ✓). So the HDiv error is elsewhere... `HDiv ℂ ℂ (ℂ → ?m.209 s)` — the unifier, when matching `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` against `ContinuousAt ?f w` with ?f a metavariable — it must abstract w — higher-order pattern unification — it found `Acoeff n i / (w - 1) ^ i` and tried to make ?f := fun w => ... — the HDiv error suggests the division's operands got mistyped: `Acoeff n i` : ℂ and `(w - 1) ^ i` : ℂ — HDiv ℂ ℂ ✓ — but the error says HDiv ℂ ℂ (ℂ → ?m.209 s) — the DIVISOR is `ℂ → ?m.209 s` — a function of type ℂ → (something applied to s). So `(w - 1) ^ i` elaborated as a function ℂ → ?m.209 s?? — with i replaced by a metavariable applied to s! — `?m.209 s` — YES — in the induction's insert case, the `i` in the sum body became `?m.209 s` — because my `this : ∀ s : Finset ℕ, ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — the `i` in `(w - 1) ^ i` is the BOUND sum variable i ∈ s ✓ — but the elaborator... hmm. Actually wait — the error at 229:46 is in `hden : ContinuousAt (fun w => (w - 1) ^ i) w := (continuousAt_id.sub continuousAt_const).pow _` — the `.pow _` — ContinuousAt.pow (hf) (n : ℕ) : ContinuousAt (f ^ n) x — the function `f ^ n` — Pi.pow — `(fun w => w − 1) ^ i` — Pi.pow instance: `(fun w => w − 1) ^ i` with i : ℕ ✓ — Pi.pow : Pow (α → β) ℕ (fun _ => Pow β) — HDiv ℂ ℂ (ℂ → ?m.5) — NO that's HDiv not HPow... The hnum.div hden line (229?) — `exact hnum.div hden (pow_ne_zero _ hw1)` — ContinuousAt.div's result (f/g) — Pi.div — HDiv (ℂ→?) — the error HDiv ℂ ℂ (ℂ → ?m.5) — the DIVIDEND is ℂ, divisor ℂ, result ℂ → ?m.5 — THREE different types in HDiv?? HDiv takes α β γ (one type + output): HDiv ℂ ℂ (ℂ → ?m.5) means dividing ℂ by ℂ to get a ℂ → ?m.5 function?! That's the instance synthesis failing to find HDiv ℂ ℂ (ℂ → ?m.5) — because the EXPECTED result of `hnum.div hden _` is the hterm goal `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — ContinuousAt F w with F := fun w => Acoeff n i / (w−1)^i — and hnum.div hden gives ContinuousAt ((fun w => Acoeff n i) / (fun w => (w−1)^i)) w — F vs that: unify `fun w => Acoeff n i / (w−1)^i` with `(fun w => Acoeff n i) / (fun w => (w−1)^i)` — by Pi.div_apply: LHS-of-Pi.div at w: (f/g) w = f w / g w = Acoeff n i / (w−1)^i ✓ — the unifier has to synthesize the division `Acoeff n i / (w - 1) ^ i` where it needs HDiv ℂ ℂ ℂ — but the error shows HDiv ℂ ℂ (ℂ → ?m.5) — the divisor `(w - 1) ^ i` — with i FREE — in the unification, i became ?m.5 applied?? — `?m.5` at 229 and `?m.209 s` at 237 — in 237 (the induction insert case), the goal after rw [Finset.sum_insert has] has the term `Acoeff n a / (w - 1) ^ a` — with a renamed... `?m.209 s` — the unifier created a metavariable applied to s. This is the classic "metavariable in the goal from a bad statement" — the hterm statement `∀ i : ℕ, ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — when applied `hterm a`, gives ContinuousAt (fun w => Acoeff n a / (w−1)^a) w ✓ fine... I'm going in circles with the text display. The root issue is likely my hterm's `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` vs the `this`'s `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — in `this`, the sum is over complex values ✓ with w the outer variable — Lean elaborates `ContinuousAt (∑ i ∈ s, BODY) w` with f := fun w => ∑ i ∈ s, BODY ✓ — BUT the elaborator must figure out that w in BODY is the SAME w as the point — it does via the lambda... Actually NO — `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — here the whole first argument is an EXPRESSION containing w — Lean treats it as `ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w-1)^i) w`? NO — Lean does NOT automatically lambda-abstract! The first arg to ContinuousAt is just an expression of type ℂ?? — ContinuousAt (f : α → β) (x : α) — the first arg must be a FUNCTION. `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` is a ℂ value, not a function! So Lean coerces/unifies it as fun w => ... via eta-expansion during unification with ContinuousAt's signature — and THAT's where the HDiv ℂ ℂ (ℂ → ?m) comes from: Lean is trying to make the ℂ expression into a function ℂ → ? — by eta-expansion, treating the whole `Acoeff n i / (w-1)^i` — with i metavariabled... RIGHT — the fix: make the function explicit everywhere: `ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w`. Let me fix tail_continuousAt's statements: ``` lemma tail_continuousAt {n : ℕ} {w : ℂ} (hw : w ≠ 1) : ContinuousAt (fun w => ∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by have hterm : ∀ i : ℕ, ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w := ... have : ∀ s : Finset ℕ, ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w := by intro s induction s using Finset.induction with | empty => simp | insert has hs => rename_i a s rw [Finset.sum_insert has] exact ContinuousAt.add hs (hterm a) exact this _ ``` The insert case goal: ContinuousAt (fun w => Acoeff n a / (w−1)^a + ∑ i ∈ s, ...) w — ContinuousAt.add hs (hterm a) : ContinuousAt ((fun w => ∑...) + (fun w => term)) — Pi.add — matches via Pi.add_apply ✓. Same for tail_continuousAt's main statement — add `fun w =>`. AND the Gprim eta issues (lines 179/189): use `show` with the explicit family form. Let me apply all these.
Root cause found: the `ContinuousAt` statements need explicit `fun w =>` lambdas. Fixing along with the eta-form `show` for the sum differentiability.
tool: Bash
input
{
  "command": "cd /d/Python/Quantum/research/lean/NguyenRH1 && python - << 'PYEOF'\np = 'NguyenRH1/LiPrincipal.lean'\ns = open(p, encoding='utf-8').read()\n\n# 1. Gprim_differentiableAt: show family form\ns = s.replace(\"\"\"  unfold Gprim\n  apply DifferentiableAt.sum\n  intro i hi\n  apply DifferentiableAt.mul (differentiableAt_const _)\"\"\",\n\"\"\"  unfold Gprim\n  show DifferentiableAt \u2102 (\u2211 i \u2208 Finset.Icc 2 (n + 1),\n    fun w : \u2102 => -(Acoeff n i / (\u2191i - 1)) * (w - 1) ^ (-(\u2191i - 1))) w\n  apply DifferentiableAt.sum\n  intro i hi\n  apply DifferentiableAt.mul (differentiableAt_const _)\"\"\")\n\n# 2. deriv_Gprim: show family form\ns = s.replace(\"\"\"  unfold Gprim\n  rw [deriv_sum (fun i hi => ?_)]\"\"\",\n\"\"\"  show deriv (\u2211 i \u2208 Finset.Icc 2 (n + 1),\n    fun w : \u2102 => -(Acoeff n i / (\u2191i - 1)) * (w - 1) ^ (-(\u2191i - 1))) w = _\n  rw [deriv_sum (fun i hi => ?_)]\"\"\")\n\n# 3. tail_continuousAt: explicit fun w =>\ns = s.replace(\"\"\"lemma tail_continuousAt {n : \u2115} {w : \u2102} (hw : w \u2260 1) :\n    ContinuousAt (\u2211 i \u2208 Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by\"\"\",\n\"\"\"lemma tail_continuousAt {n : \u2115} {w : \u2102} (hw : w \u2260 1) :\n    ContinuousAt (fun w => \u2211 i \u2208 Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by\"\"\")\ns = s.replace(\"\"\"  have : \u2200 s : Finset \u2115, ContinuousAt (\u2211 i \u2208 s, Acoeff n i / (w - 1) ^ i) w := by\"\"\",\n\"\"\"  have : \u2200 s : Finset \u2115, ContinuousAt (fun w => \u2211 i \u2208 s, Acoeff n i / (w - 1) ^ i) w := by\"\"\")\n\nopen(p, 'w', encoding='utf-8').write(s)\nprint(\"patched\")\nPYEOF\nexport PATH=\"$HOME/.elan/bin:$PATH\" && lake env lean NguyenRH1/LiPrincipal.lean 2>&1 | head -40",
  "description": "Fix lambda abstraction issues, recompile",
  "timeout": 420000
}
raw content_json (database row)
[{"type":"thinking","thinking":"I see the HDiv error source: in `hnum.div hden (pow_ne_zero _ hw1)` — `hnum.div` — ContinuousAt.div — the dot-projection: hnum : ContinuousAt (fun w => Acoeff n i) w — `.div hden (pow_ne_zero _ hw1)` — ContinuousAt.div (hf) (hg) (hz : g x ≠ 0) : ContinuousAt (f / g) x — the result (f/g) — Pi division: HDiv (ℂ → ?) — the ERROR `HDiv ℂ ℂ (ℂ → ?m.5)` — hmm — ContinuousAt.div's result: `ContinuousAt (f / g) x` where (f / g) : α → β with pointwise division — instance `Pi.div` — the division f/g of FUNCTIONS — the goal (after `exact`) is the hterm statement `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — Lean must unify `(fun w => Acoeff n i) / (fun w => (w−1)^i)` with `fun w => Acoeff n i / (w−1)^i` — Pi.div_apply defeq ✓ — but the ERROR is at 229:46 which is... line 229 = `exact hnum.div hden (pow_ne_zero _ hw1)`?? — let me count: 229 is `have hden : ContinuousAt (fun w => (w - 1) ^ i) w :=` region or the `(continuousAt_id.sub continuousAt_const).pow _` line (229:46 is the `.pow _` position). `.pow _` — ContinuousAt.pow (h) (n) — with `_` — the HDiv error at that position?? no...\n\nActually — the errors at 229:46 and 237:48 mention `HDiv ℂ ℂ (ℂ → ?m.209 s)` — `?m.209 s` — a function applied to s! In the induction case: `ContinuousAt.add hs (hterm a)` — hs : ContinuousAt (∑ i ∈ s, ...) — wait — ContinuousAt.add (hf) (hg) : ContinuousAt (f + g) x — the goal (after rw [Finset.sum_insert has]) is `ContinuousAt (∑ i ∈ insert a s, ...) w` which rw turned into `ContinuousAt (∑ i ∈ s, ... + Acoeff n a / (w−1)^a) w`?? — Finset.sum_insert : ∑ i ∈ insert a s, f i = f a + ∑ i ∈ s, f i ✓ — so goal: `ContinuousAt (Acoeff n a / (w−1)^a + ∑ i ∈ s, Acoeff n i / (w−1)^i) w` — ContinuousAt.add hs (hterm a) : ContinuousAt ((∑-function) + (term-function)) — via Pi.add — matches the goal up to add order ✓ should work...\n\nThe HDiv error `ℂ → ?m.209 s` — something is divided by a FUNCTION. Where? `Acoeff n i / (w - 1) ^ i` — WAIT. I bet the issue is `(w - 1) ^ i` — if `i` here is NOT the natural number exponent but got elaborated as... no. Hmm, `Acoeff n i / (w - 1) ^ i` — Lean parses this as `HDiv.hDiv (Acoeff n i) ((w - 1) ^ i)` — HDiv ℂ ℂ — fine...\n\nUnless — `Acoeff n i` is not ℂ! Acoeff def: `Acoeff (n i : ℕ) : ℂ := iteratedDeriv (n + 1 - i) ... 1 / Nat.factorial (n + 1 - i)` — hmm wait — the elaboration of `Acoeff n i` requires Acoeff to be fully elaborated — if Acoeff's def has an ERROR (line 178/188 simp failures are in DIFFERENT lemmas — Gprim_differentiableAt/deriv_Gprim), Acoeff itself might be fine... The errors at 178/188 are `unfold Gprim` + `apply DifferentiableAt.sum` / `rw [deriv_sum ...]` — those are the NEXT lemmas. Acoeff compiled (no error at 162 now after Nat.factorial fix — the error list no longer shows 162).\n\nSo the HDiv error is genuinely in tail_continuousAt. `HDiv ℂ ℂ (ℂ → ?m.209 s)` — the `?m.209 s` — an application of a metavariable to s — in the `insert` case, `rename_i a s` renamed s — the goal after `rw [Finset.sum_insert has]`: `ContinuousAt (Acoeff n a / (w - 1) ^ a + ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — and `ContinuousAt.add hs (hterm a)` — ContinuousAt.add : ContinuousAt (f + g) x with (f + g) via Pi.add — Pi.add's instance HDiv?? no, Pi.add is HAdd. The HDiv error — hmm — `ContinuousAt.add` might not exist! Check: `ContinuousAt.add (hf : ContinuousAt f x) (hg : ContinuousAt g x) : ContinuousAt (f + g) x` ✓ exists I'm sure. \n\nOK let me just look at line numbers precisely: 229:46 and 237:48. Line 229 in the current file — the `have hden` line or `.pow _`. 237 = `exact ContinuousAt.add hs (hterm a)`. The HDiv error at 237:48 = the `hterm a` position — hterm a : ContinuousAt (fun w => Acoeff n a / (w - 1) ^ a) w — the HDiv ℂ ℂ (ℂ → ?m.209 s) — `?m.209 s` — s is the Finset! `Acoeff n i / (w - 1) ^ i` — WAIT. I see it: in hterm's statement I wrote `fun w => Acoeff n i / (w - 1) ^ i` — Lean might parse `Acoeff n i / (w - 1) ^ i` as `(Acoeff n i / (w - 1)) ^ i`?? — no, ^ binds tighter... UNLESS the elaboration made `(w - 1) ^ i` into `HPow.hPow (w-1) i` ✓ fine.\n\nHold on — `?m.209 s` — s applied — the sum `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` — the summand is a FUNCTION of i (with w FIXED — this is a sum over ℂ values, not functions!). The sum `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` is a COMPLEX NUMBER (sum of complex terms) ✓ — the ContinuousAt is of a CONSTANT function?? NO — tail_continuousAt's statement: `ContinuousAt (∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w` — the sum is a fixed complex number and ContinuousAt of a constant — THAT'S NOT WHAT I WANT! The tail sum as a function of w: I need `fun w => ∑ i, Acoeff n i / (w - 1) ^ i`!! In rectInt_deriv_eq_zero's hGc hypothesis I need ContinuousAt (deriv (Gprim n)) s — with deriv_Gprim: deriv (Gprim n) w = ∑ i, Acoeff n i / (w - 1) ^ i — as functions of w. But tail_continuousAt's statement lacks the `fun w =>`!! The goal `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — the sum over i of (Acoeff n i / (w−1)^i) — this IS a function of w implicitly?? NO — `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` with w : ℂ a VARIABLE — the sum's VALUE depends on w — so the expression IS a function of w (the lambda is implicit in the proposition). ContinuousAt (expr-involving-w) w — Lean elaborates ContinuousAt f w with f := fun w => expr ✓ — that's how it works (the `this : ∀ s : Finset ℕ, ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — with w free — Lean generalizes f := fun w => ∑ i ∈ s, ... ✓). So the HDiv error is elsewhere... `HDiv ℂ ℂ (ℂ → ?m.209 s)` — the unifier, when matching `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` against `ContinuousAt ?f w` with ?f a metavariable — it must abstract w — higher-order pattern unification — it found `Acoeff n i / (w - 1) ^ i` and tried to make ?f := fun w => ... — the HDiv error suggests the division's operands got mistyped: `Acoeff n i` : ℂ and `(w - 1) ^ i` : ℂ — HDiv ℂ ℂ ✓ — but the error says HDiv ℂ ℂ (ℂ → ?m.209 s) — the DIVISOR is `ℂ → ?m.209 s` — a function of type ℂ → (something applied to s). So `(w - 1) ^ i` elaborated as a function ℂ → ?m.209 s?? — with i replaced by a metavariable applied to s! — `?m.209 s` — YES — in the induction's insert case, the `i` in the sum body became `?m.209 s` — because my `this : ∀ s : Finset ℕ, ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — the `i` in `(w - 1) ^ i` is the BOUND sum variable i ∈ s ✓ — but the elaborator... hmm.\n\nActually wait — the error at 229:46 is in `hden : ContinuousAt (fun w => (w - 1) ^ i) w := (continuousAt_id.sub continuousAt_const).pow _` — the `.pow _` — ContinuousAt.pow (hf) (n : ℕ) : ContinuousAt (f ^ n) x — the function `f ^ n` — Pi.pow — `(fun w => w − 1) ^ i` — Pi.pow instance: `(fun w => w − 1) ^ i` with i : ℕ ✓ — Pi.pow : Pow (α → β) ℕ (fun _ => Pow β) — HDiv ℂ ℂ (ℂ → ?m.5) — NO that's HDiv not HPow... The hnum.div hden line (229?) — `exact hnum.div hden (pow_ne_zero _ hw1)` — ContinuousAt.div's result (f/g) — Pi.div — HDiv (ℂ→?) — the error HDiv ℂ ℂ (ℂ → ?m.5) — the DIVIDEND is ℂ, divisor ℂ, result ℂ → ?m.5 — THREE different types in HDiv?? HDiv takes α β γ (one type + output): HDiv ℂ ℂ (ℂ → ?m.5) means dividing ℂ by ℂ to get a ℂ → ?m.5 function?! That's the instance synthesis failing to find HDiv ℂ ℂ (ℂ → ?m.5) — because the EXPECTED result of `hnum.div hden _` is the hterm goal `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — ContinuousAt F w with F := fun w => Acoeff n i / (w−1)^i — and hnum.div hden gives ContinuousAt ((fun w => Acoeff n i) / (fun w => (w−1)^i)) w — F vs that: unify `fun w => Acoeff n i / (w−1)^i` with `(fun w => Acoeff n i) / (fun w => (w−1)^i)` — by Pi.div_apply: LHS-of-Pi.div at w: (f/g) w = f w / g w = Acoeff n i / (w−1)^i ✓ — the unifier has to synthesize the division `Acoeff n i / (w - 1) ^ i` where it needs HDiv ℂ ℂ ℂ — but the error shows HDiv ℂ ℂ (ℂ → ?m.5) — the divisor `(w - 1) ^ i` — with i FREE — in the unification, i became ?m.5 applied?? — `?m.5` at 229 and `?m.209 s` at 237 — in 237 (the induction insert case), the goal after rw [Finset.sum_insert has] has the term `Acoeff n a / (w - 1) ^ a` — with a renamed... `?m.209 s` — the unifier created a metavariable applied to s. This is the classic \"metavariable in the goal from a bad statement\" — the hterm statement `∀ i : ℕ, ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` — when applied `hterm a`, gives ContinuousAt (fun w => Acoeff n a / (w−1)^a) w ✓ fine...\n\nI'm going in circles with the text display. The root issue is likely my hterm's `ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w` vs the `this`'s `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — in `this`, the sum is over complex values ✓ with w the outer variable — Lean elaborates `ContinuousAt (∑ i ∈ s, BODY) w` with f := fun w => ∑ i ∈ s, BODY ✓ — BUT the elaborator must figure out that w in BODY is the SAME w as the point — it does via the lambda... Actually NO — `ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w` — here the whole first argument is an EXPRESSION containing w — Lean treats it as `ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w-1)^i) w`? NO — Lean does NOT automatically lambda-abstract! The first arg to ContinuousAt is just an expression of type ℂ?? — ContinuousAt (f : α → β) (x : α) — the first arg must be a FUNCTION. `∑ i ∈ s, Acoeff n i / (w - 1) ^ i` is a ℂ value, not a function! So Lean coerces/unifies it as fun w => ... via eta-expansion during unification with ContinuousAt's signature — and THAT's where the HDiv ℂ ℂ (ℂ → ?m) comes from: Lean is trying to make the ℂ expression into a function ℂ → ? — by eta-expansion, treating the whole `Acoeff n i / (w-1)^i` — with i metavariabled... \n\nRIGHT — the fix: make the function explicit everywhere: `ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w`. Let me fix tail_continuousAt's statements:\n```\nlemma tail_continuousAt {n : ℕ} {w : ℂ} (hw : w ≠ 1) :\n    ContinuousAt (fun w => ∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by\n  have hterm : ∀ i : ℕ, ContinuousAt (fun w => Acoeff n i / (w - 1) ^ i) w := ...\n  have : ∀ s : Finset ℕ, ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w := by\n    intro s\n    induction s using Finset.induction with\n    | empty => simp\n    | insert has hs =>\n      rename_i a s\n      rw [Finset.sum_insert has]\n      exact ContinuousAt.add hs (hterm a)\n  exact this _\n```\nThe insert case goal: ContinuousAt (fun w => Acoeff n a / (w−1)^a + ∑ i ∈ s, ...) w — ContinuousAt.add hs (hterm a) : ContinuousAt ((fun w => ∑...) + (fun w => term)) — Pi.add — matches via Pi.add_apply ✓.\n\nSame for tail_continuousAt's main statement — add `fun w =>`. AND the Gprim eta issues (lines 179/189): use `show` with the explicit family form.\n\nLet me apply all these.","signature":""},{"type":"text","text":"Root cause found: the `ContinuousAt` statements need explicit `fun w =>` lambdas. Fixing along with the eta-form `show` for the sum differentiability."},{"type":"tool_use","id":"Bash_270","name":"Bash","input":{"command":"cd /d/Python/Quantum/research/lean/NguyenRH1 && python - << 'PYEOF'\np = 'NguyenRH1/LiPrincipal.lean'\ns = open(p, encoding='utf-8').read()\n\n# 1. Gprim_differentiableAt: show family form\ns = s.replace(\"\"\"  unfold Gprim\n  apply DifferentiableAt.sum\n  intro i hi\n  apply DifferentiableAt.mul (differentiableAt_const _)\"\"\",\n\"\"\"  unfold Gprim\n  show DifferentiableAt ℂ (∑ i ∈ Finset.Icc 2 (n + 1),\n    fun w : ℂ => -(Acoeff n i / (↑i - 1)) * (w - 1) ^ (-(↑i - 1))) w\n  apply DifferentiableAt.sum\n  intro i hi\n  apply DifferentiableAt.mul (differentiableAt_const _)\"\"\")\n\n# 2. deriv_Gprim: show family form\ns = s.replace(\"\"\"  unfold Gprim\n  rw [deriv_sum (fun i hi => ?_)]\"\"\",\n\"\"\"  show deriv (∑ i ∈ Finset.Icc 2 (n + 1),\n    fun w : ℂ => -(Acoeff n i / (↑i - 1)) * (w - 1) ^ (-(↑i - 1))) w = _\n  rw [deriv_sum (fun i hi => ?_)]\"\"\")\n\n# 3. tail_continuousAt: explicit fun w =>\ns = s.replace(\"\"\"lemma tail_continuousAt {n : ℕ} {w : ℂ} (hw : w ≠ 1) :\n    ContinuousAt (∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by\"\"\",\n\"\"\"lemma tail_continuousAt {n : ℕ} {w : ℂ} (hw : w ≠ 1) :\n    ContinuousAt (fun w => ∑ i ∈ Finset.Icc 2 (n + 1), Acoeff n i / (w - 1) ^ i) w := by\"\"\")\ns = s.replace(\"\"\"  have : ∀ s : Finset ℕ, ContinuousAt (∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w := by\"\"\",\n\"\"\"  have : ∀ s : Finset ℕ, ContinuousAt (fun w => ∑ i ∈ s, Acoeff n i / (w - 1) ^ i) w := by\"\"\")\n\nopen(p, 'w', encoding='utf-8').write(s)\nprint(\"patched\")\nPYEOF\nexport PATH=\"$HOME/.elan/bin:$PATH\" && lake env lean NguyenRH1/LiPrincipal.lean 2>&1 | head -40","description":"Fix lambda abstraction issues, recompile","timeout":420000},"extra_content":null}]