← Session 31 — ii′-5f: tight R-bound 10.5/48 (piece 3 + pinch)
thinking (18634 chars)
1. Line 3918: exp_point4848_le — the norm_num at h left `7743114841069643681 / 4768371582031250000 ≤ Real.exp (303/625)` and a✝ : 1.6239 < Real.exp 0.4848 — the partial sum didn't reach 1.6239?! Σ_{k<7} 0.4848^k/k! = 1.623851 — hmm — the norm_num normalized the sum to the giant rational `7743114841069643681/4768371582031250000` — let me compute: 7743114841069643681/4768371582031250000 = 1.62385·... = 1.623846. And 1.6239 — the target Real.exp 0.4848 ≤ 1.6239 needs the partial sum ≥ 1.6239?? NO — the partial sum is a LOWER bound for exp: Σ_{k<7} = 1.623846 ≤ e^0.4848 — and I want e^0.4848 ≤ 1.6239 — the partial sum doesn't prove THAT (it's a lower bound on exp, giving exp ≥ 1.623846 — useless for an upper bound!!). WAIT — Real.sum_le_exp_of_nonneg : Σ_{k<n} x^k/k! ≤ exp x — LOWER bound on exp ✓. For exp UPPER bounds I used this for e^0.571 ≥ 23/13 etc. (lower-bound-the-exp then compare). Here I want e^0.4848 ≤ 1.6239 (UPPER) — sum_le_exp gives exp ≥ 1.623846 — WRONG DIRECTION for my lemma!!
Hold on — how did the earlier exp-upper lemmas work? E.g. log_23_13_le : log(23/13) ≤ 0.571 via 23/13 ≤ e^0.571: partial sums give e^0.571 ≥ Σ ≥ 1.769 ≥ 23/13 ✓ — there I needed e^U ≥ x (exp LOWER bound ✓ sum_le_exp works). For log_twelve_ge I need e^2.4848 ≤ 12 (exp UPPER) — sum_le_exp gives exp LOWER ✗. Hmm — but I DID use this pattern for e^2.5 ≤ 13 in §13 (exp_two_point_five_le_thirteen): via e^0.5 ≤ 1.6488 — and e^0.5 ≤ 1.6488 was proven via le_of_pow_le_pow_left₀ ((e^0.5)² ≤ 1.6488² ⟸ e ≤ 1.6488²)!! The squaring trick. For e^0.4848 ≤ 1.6239: (e^0.4848)² = e^0.9696 ≤ 1.6239² = 2.63705121 ⟸ e^0.9696 ≤ 2.63705121: e^0.9696 = e/e^0.0304 = 2.7182819/1.03087·... = 2.63691·... ≤ 2.63705 ✓ — via e^0.9696 ≤ ?: e^0.9696 ≤ 2.6371: partial sums give LOWER 2.6368-ish ✗ again (need upper). ARGH — exp upper bounds need: e^x ≤ U ⟺ 1 ≤ U·e^{−x} ⟺ e^{−x} ≥ 1/U — and e^{−x} ≥ 1−x+x²/2−x³/6 (alternating LOWER bound for x ≥ 0? e^{−x} ≥ 1−x for sure; better: e^{−x} ≥ 1−x+x²/2−x³/6 for x ≥ 0?? — the alternating stops: e^{−x} = Σ(−x)^k/k!: for x ≥ 0, the series alternates with decreasing terms after k > x: the odd-stops are LOWER bounds ✓ (Taylor with remainder: e^{−x} = T_{2m+1}(x) + e^{−ξ}x^{2m+2}/(2m+2)! ≥ T_{2m+1} since the remainder term is +). So e^{−x} ≥ 1−x+x²/2−x³/6 (k≤3, odd stop) for x ≥ 0 ✓. For x = 0.4848: e^{−0.4848} ≥ 1−0.4848+0.117516−0.018992 = 0.613724. Then e^0.4848 ≤ 1/0.613724 = 1.629415 ✗ > 1.6239. k≤5: e^{−0.4848} ≥ 1−0.4848+0.117516−0.018992+0.002302−0.000223 = 0.615803: 1/0.615803 = 1.62391·... = 1.623906 ✗ barely > 1.6239!! k≤7: +0.0000180−0.00000125 = 0.615820: 1/0.615820 = 1.623862 ≤ 1.6239 ✓. So e^0.4848 ≤ 1/0.615820·... ≤ 1.6239 via e^{−0.4848} ≥ 0.615820 (k≤7 alternating). Hmm — that's a tight 3.8e-5 margin. The alternating lower bound: e^{−x} ≥ Σ_{k≤2m+1}(−x)^k/k! — is that a clean Mathlib lemma? `Real.sum_le_exp_of_nonneg` is for positive x. For e^{−x}: exp(−x) = exp((−x)) — sum_le_exp_of_nonneg needs x ≥ 0 (the terms are positive for its use in bounds). For the alternating case I'd prove it via `Real.exp_bound'`? or via the inequality e^{-x} ≥ 1−x (Real.add_one_le_exp: 1+z ≤ e^z for all z ✓ `Real.add_one_le_exp : 1 + x ≤ exp x` for ALL x!). So e^{−0.4848} ≥ 1−0.4848 = 0.5152: e^0.4848 ≤ 1/0.5152 = 1.9410 ✗ too weak.
Alternative for log 12 ≥ 2.4848: use log 12 = log 3 + log 4 = log 3 + 2 log 2 ≥ 1.0986 + 2·0.6931471 = 1.0986+1.3862942 = 2.4848942 ≥ 2.4848 ✓!! With log 3 ≥ 1.0986 (13... log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986: e^1.0986 = 2.99991·... ≤ 3 ✓ — again exp upper — sum_le_exp gives lower 2.99986·... need ≥ 3?? e^1.0986 ≥ 3 needed for log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986 — exp upper again!!). Hmm — but wait — log 3: I have log_thirteen_le (log 13 ≤ 2.565) and earlier in the file `hlog3 : Real.log 3 ≤ 1.1` (in dirichletC2_le_one's proof) and `hlog3 : (1:ℝ) ≤ Real.log 3` (antitoneOn_log_div_sq's proof: log 3 ≥ 1 via e ≤ 3 ✓ — that's the EASY direction: log 3 ≥ 1 ⟺ 3 ≥ e ✓ exp_one_lt_d9 ✓). For log 3 ≥ 1.0986: 3 ≥ e^1.0986 — e^1.0986 = e·e^0.0986 ≤ 2.7182819·1.10363 = 2.99999·... — e^0.0986 ≤ 1.10363: partial sums give LOWER 1.1035-ish ✗ upper needed — via (e^0.0986)² = e^0.1972 ≤ 1.10363² = 1.217999·... ⟸ e^0.1972 ≤ 1.217999: partial sums LOWER 1.21793 ✗ upper... e^0.1972 ≤ 1/(1−0.1972) = 1.24579 ✗; ≤ 1/(1−0.0986)² = 1.23167 ✗; e^0.1972 = 1.21794 — sum gives lower ~1.21791, need upper ≤ 1.217999: via e^{−0.1972} ≥ 1−0.1972+0.019444−0.001278 = 0.820966: 1/0.820966 = 1.218078 ✗ > 1.217999. k≤5: +0.000063−0.0000025 = 0.821026: 1/1.218006 ✗ still. ARGH.
STOP. The clean way for log 12 ≥ 2.4848: log 12 = log(4·3) = 2·log 2 + log 3 with log 3 ≥ 1.0986. For log 3 ≥ 1.0986 — how about log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986: e^1.0986 ≤ 3 — via e^1.0986 = (e^{1.0986/2})² ≤ (partial-upper?)...
OK here's the CLEAN general trick for exp upper bounds I should have used all along: e^x ≤ 1/(1−x) for 0 ≤ x < 1 (from e^{−x} ≥ 1−x: 1−x ≤ e^{−x} ⟹ e^x ≤ 1/(1−x) ✓ Real.add_one_le_exp gives 1+(−x) ≤ e^{−x} ✓). And e^x = (e^{x/n})ⁿ ≤ 1/(1−x/n)ⁿ. For e^0.4848: n = 4: e^0.4848 ≤ 1/(1−0.1212)⁴ = 1/0.8788⁴: 0.8788² = 0.772289; ⁴ = 0.596431: 1/0.596431 = 1.676645 ✗ > 1.6239. n = 8: 0.4848/8 = 0.0606: 1/(1−0.0606)⁸ = 1/0.9394⁸: 0.9394² = 0.882472; ⁴ = 0.778757; ⁸ = 0.606462: 1/0.606462 = 1.648911 ✗. n = 16: 0.0303: 1/(1−0.0303)¹⁶: 0.9697^16 = e^{16·ln 0.9697} = e^{16·(−0.030768)} = e^{−0.492291} = 0.611220: 1/0.611220 = 1.636078 ✗. The 1/(1−x/n)ⁿ route converges to e^x from above but slowly (like the earlier computations). True e^0.4848 = 1.623809·... — so even 1.6239 IS close to the true value (margin 9e-5) — the alternating-remainder route (k≤7) reached 1.623862 ✓ barely.
For log 3 ≥ 1.0986 (needed for log 12 via 2·log 2+log 3): true log 3 = 1.0986123 — need lower bound ≥ 1.0986 (margin 1.2e-5!). Via the LOG-SERIES at a rational: log 3 = log(e·(3/e)) = 1 + log(3/e): 3/e = 1.103639: log(1.103639) = log(1+x), x = 0.103639: log(1+x) ≥ x−x²/2+x³/3−x⁴/4 (my log_one_add_ge!): 0.103639−0.005371+0.000371−0.000029 = 0.098610·... = 0.0986104. log 3 ≥ 1+0.0986104 = 1.0986104 ≥ 1.0986 ✓ (margin 1.04e-5 — TIGHT but exact ✓ — with x = 3/e−1: need x ≤ 0.10364 (rational upper: 3/e ≤ 3/2.7182818 = 1.1036395·... ⟹ x = 3/e−1 ≤ 0.1036395 — use 0.10364 as the rational x-bound: log(1+x) ≥ log(1+0.1036395·...)?? — log increasing: log(3/e) = log(1+x) with x = 3/e−1: I need a LOWER bound on log(1+x) — the alternating bound is increasing in x, so I need x ≥ x₀: x = 3/e−1 ≥ 3/2.7182819−1 = 0.1036388·... — with e ≤ 2.7182819: 3/e ≥ 3/2.7182819 = 1.10363881·... ⟹ x ≥ 0.10363881. Then log(1+x) ≥ x−x²/2+x³/3−x⁴/4 evaluated at x ≥ 0.10363881 — the alternating poly p(x) = x−x²/2+x³/3−x⁴/4 is INCREASING for x ∈ [0,1]? p′(x) = 1−x+x²−x³ > 0 ✓ (1−x+x²−x³ = (1−x)+x²(1−x) = (1−x)(1+x²) ≥ 0 for x ≤ 1 ✓). So p(x) ≥ p(0.10363881) — but the bound p(x) ≤ log(1+x) holds for all x ≥ 0 (log_one_add_ge) — so log(1+x) ≥ p(x) ≥ p(0.10363881) (p increasing — PROVE p increasing? or just: log(1+x) ≥ p(x) and p(x) ≥ p(x₀) needs monotonicity of p — ugh. SIMPLER: use the LARGER rational x₀ = 0.10363 with log(1+x) ≥ p(x) — NO WAIT — the bound log(1+x) ≥ p(x) holds at the ACTUAL x = 3/e−1 (whatever it is) — and x ≥ 0.10363 ⟹ p(x) ≥ p(0.10363) if p is increasing. p(0.10363) = 0.10363−0.0053696+0.0003709−0.0000288 = 0.0986025. log 3 ≥ 1.0986025 ≥ 1.0986 ✓ (margin 2.5e-6 — TOO TIGHT!). Hmm — p(x) at the true x = 0.10363881: 0.10363881−0.00537049+0.00037125−0.00002886 = 0.09861071 — so log 3 ≥ 1.09861071. The margin over 1.0986 is 1.07e-5. To prove p increasing on [0.10363, x]: p′(x) = (1−x)(1+x²) ≥ 0 ✓ for x ≤ 1 — formalize via antitoneOf/MonotoneOn-of-deriv-nonneg (the antitoneOn_of_deriv_nonpos pattern has a monotone sibling: monotoneOn_of_deriv_nonneg ✓ exists presumably).
Then log 12 = 2·log 2 + log 3 ≥ 2·0.6931471+1.0986 = 2.4848942·... wait — use the EXACT lower bounds: log 2 ≥ 0.6931471 (log_two_gt_d9) and log 3 ≥ 1+0.09861071·... — with the p-increasing subtlety: log(1+x) ≥ p(x) at x = 3/e−1 — and x ≥ 3/2.7182819 − 1 — compute p(3/2.7182819−1) EXACTLY as a rational: x₀ = 3/2.7182819 − 1 = 0.10363883·... — p(x₀) as a rational number: x₀ = 3/2.7182819−1 — p(x₀) = x₀−x₀²/2+x₀³/3−x₀⁴/4 — norm_num can compute this with x₀ = (3/2.7182819 − 1) — the division inside — norm_num handles divisions of literals ✓. Then log 3 ≥ 1+p(x₀)?? — NO — the bound is log(1+x) ≥ p(x) with x = 3/e−1, and p increasing ⟹ p(x) ≥ p(x₀) since x ≥ x₀ (e ≤ 2.7182819 ⟹ 3/e ≥ 3/2.7182819 = x₀+1 ⟹ x ≥ x₀ ✓). So log 3 ≥ 1 + p(x₀) with p increasing on [x₀, x] — need x ≤ 1 for p′ ≥ 0 ✓ (x ≤ 0.11 ≤ 1 ✓).
Hmm — p increasing on [0, 1.1] needs the monotoneOn_of_deriv_nonneg proof (~30 lines). Fine.
log 12 ≥ 2·0.6931471 + (1+p(x₀)) with p(x₀) = norm_num-computed ≈ 0.09861071: total ≥ 1.3862942+1.09861071 = 2.48490491 ≥ 2.4848 ✓ (margin 1.05e-4 ✓).
Hmm — this is getting heavy. ALTERNATIVE much simpler: log 12 ≥ 2.4848 ⟺ 12 ≥ e^2.4848 ⟺ 12⁴ ≥ e^{9.9392}·... no. ⟺ log 12 ≥ 2.4848 ⟸ log 12 = log(16·0.75) = 4 log 2 + log(3/4) = 4·0.6931471 + log 0.75: log 0.75 = −log(4/3) ≥ −(1/3) (log z ≤ z−1: log(4/3) ≤ 1/3 = 0.333333): log 12 ≥ 2.7725887−0.3333334 = 2.4392553 ✗ < 2.4848. Better: log(4/3) ≤ (4/3−1)·... or the finer: log(4/3) = −log(3/4): −log(1−y), y = 1/4: −log(1−1/4) ≤ y+y²/2+y³/(3(1−y)) = 0.25+0.03125+0.015625/(3·0.75 = 2.25) = 0.25+0.03125+0.006944 = 0.288194. log 12 ≥ 2.7725887−0.288194 = 2.4843947 ✗ < 2.4848 (by 4e-4!). One more term: y+y²/2+y³/3+y⁴/(4(1−y)) = 0.25+0.03125+0.005208+0.000651/1 = 0.287109·... wait my neg_log_one_sub_le only has 3 terms. Extend? log(4/3) ≤ 0.287109+0.000651 = 0.287760?? hmm — recompute: −log(1−y) = y + y²/2 + y³/3 + y⁴/4·(1/(1−y))·... — with the 3-term bound (y+y²/2+y³/(3(1−y))): 0.25+0.03125+0.015625/2.25 = 0.288194. The TRUE log(4/3) = 0.287682. log 12 = 4·0.6931471−0.288194·... hmm wait — log 12 = 4 log 2 − log(4/3)?? log 12 = log(16·(12/16)) = 4 log 2 + log(3/4) = 4 log 2 − log(4/3) ✓ ≥ 2.7725887 − 0.288194 = 2.4843947 ✗ short by 4e-4. With a 4-term bound (y+y²/2+y³/3+y⁴/(4(1−y))): 0.25+0.03125+0.005208+0.000651 = 0.287109·... hmm that's LESS than the 3-term (0.288194)? The 4-term: y³/3 = 0.005208 (vs y³/(3(1−y)) = 0.006944) + y⁴/(4(1−y)) = 0.00390625/3 = 0.001302·... 0.25+0.03125+0.005208+0.001302 = 0.28776. Still ≥ true 0.287682 ✓: log 12 ≥ 2.7725887−0.287760 = 2.4848287 ≥ 2.4848 ✓ (margin 2.87e-5 — tight but exact ✓). Requires a 4-term version of neg_log_one_sub_le: −log(1−y) ≤ y+y²/2+y³/3+y⁴/(4(1−y)) via 1/(1−t) ≤ 1+t+t²+t³/(1−y) on [0,y] — same integral machine (1 ≤ (1−t)(1+t+t²+t³/(1−y)) = 1−t³+t³(1−t)/(1−y) ⟺ t³ ≤ t³(1−t)/(1−y) ⟺ 1−y ≤ 1−t ⟺ t ≤ y ✓). EASY extension.
So plan for log_twelve_ge: log 12 = 4·log 2 − log(4/3) ≥ 4·0.6931471 − 0.287760 = 2.4848287 ≥ 2.4848 ✓ with the 4-term neg_log bound: log(4/3) = −log(3/4) = −log(1−1/4) ≤ 1/4+1/32+1/192+1/(1024·(4·(3/4)))·... compute: y = 1/4: y+y²/2+y³/3+y⁴/(4(1−y)) = 0.25+0.03125+0.005208333+0.00390625/3 = 0.25+0.03125+0.005208333+0.001302083 = 0.287760416 ≤ 0.28777 ✓ (margin 1e-5). Then log 12 ≥ 4·0.6931471−0.28777 = 2.7725884−0.28777 = 2.4848184·... hmm — 4·0.6931471 = 2.7725884: −0.28777 = 2.4848184 ≥ 2.4848 ✓ (margin 1.84e-5). Use the sharper internal: 2.7725884−0.287760416 = 2.484827984 ✓.
And log 4/3 = −log(3/4): −log(3/4) = −log(1−1/4) — the 4-term lemma: `neg_log_one_sub_le_four : 0 ≤ y → y < 1 → -Real.log (1-y) ≤ y + y^2/2 + y^3/3 + y^4/(4*(1-y))`.
For log_2_5024_le (log 2.5024 ≤ 0.9173): e^0.9173 ≥ 2.5024 — sum_le_exp partial sums ✓ (worked — my partial sum computed 2.50251073 ≥ 2.5024 ✓ — the norm_num at h in that proof should verify Σ ≥ 2.5024: the norm_num reduced h to the giant rational `... ≤ Real.exp (303/625)`?? — 0.9173 = 303/625?? — 303/625 = 0.4848!! — the error at 3918 was about exp (303/625) = exp 0.4848 — that was exp_point4848_le's failure (wrong direction). The log_2_5024 proof used e^0.9173 with partial sums — that's the CORRECT direction (exp lower) ✓ keep it.
2. Line 3936: `Real.le_log_iff_exp_le ?m.165 12` — le_log_iff_exp_le's signature: `Real.le_log_iff_exp_le (hx : 0 < x) : a ≤ Real.log x ↔ Real.exp a ≤ x` — it takes the POINT x as an EXPLICIT/implicit arg and a as implicit: `Real.le_log_iff_exp_le (hx : 0 < x) : a ≤ log x ↔ exp a ≤ x` — so `Real.le_log_iff_exp_le (show (0:ℝ) < 12 by norm_num)` : a ≤ log 12 ↔ exp a ≤ 12 — then `.mp`?? I want 2.4848 ≤ log 12 ⟸ exp 2.4848 ≤ 12: (le_log_iff_exp_le).mpr h1? or rw [h5]: the goal `2.4848 ≤ Real.log 12` — rw [Real.le_log_iff_exp_le (0<12)] turns it into Real.exp 2.4848 ≤ 12 = h1 ✓ — but the error shows the implicit ?m.165 unresolved — because rw [h5] with h5 := Real.le_log_iff_exp_le (...) — the `a` in the iff is a METAVAR — rw [h5] rewrites `?a ≤ Real.log 12` — the goal has 2.4848 ≤ log 12 ✓ should unify ?a := 2.4848 — the error "don't know how to synthesize implicit argument x" — x is the POINT (12 here) — the implicit x in le_log_iff_exp_le is the point?! Signature: `Real.le_log_iff_exp_le {a : ℝ} {x : ℝ} (hx : 0 < x) : a ≤ Real.log x ↔ Real.exp a ≤ x` — x implicit (from hx). My h5 := Real.le_log_iff_exp_le (by norm_num : (0:ℝ) < 12) ✓ determines x = 12. Then `rw [h5]` — h5 is an IFF — rw with an iff rewrites `a ≤ Real.log 12 ↔ ...` — the goal `2.4848 ≤ Real.log 12` — the iff's LHS is `?a ≤ Real.log 12` ✓ unifies ✓... The error "don't know how to synthesize implicit argument x" — maybe the `by norm_num : (0:ℝ) < 12` ascription issue again (the `:` binding). Use (show (0:ℝ) < 12 by norm_num).
3. Line 3921: the goal `2.4848 ≤ Real.log 12` unsolved — cascade of the h5 issue: after rw [h5] failed... restructure:
```
have h5 : (2.4848 : ℝ) ≤ Real.log 12 := by
rw [Real.le_log_iff_exp_le (show (0 : ℝ) < 12 by norm_num)]
exact h1
exact h5
```
Or directly: exact (Real.le_log_iff_exp_le (show (0:ℝ) < 12 by norm_num)).mpr h1.
4. Line 3964: "Failed to rewrite using equation theorems for pinchF" — rw [pinchF] on a private def failed?? — I made pinchF/pinchF' `private def` — private defs can't be unfolded by rw from outside?? — I changed them to plain `def` in the final edit (checked: the Edit I applied has `def pinchF` and `def pinchF'` — line 3964's error is at `rw [pinchF]` in pinchF_at_critical — "Failed to rewrite using equation theorems" — the def unfolding: rw [pinchF] unfolds the def via its equation — for a plain def this should work... unless pinchF is a def with an explicit argument pattern: `def pinchF (L : ℝ) : ℝ := 11.6321 * Real.log L - 4.6484 * L` — rw [pinchF] rewrites `pinchF 2.5024` → the body ✓ should work. "Failed to rewrite using equation theorems" — hmm — maybe the issue is the `def` needs the unfold lemma: use `rw [show pinchF 2.5024 = 11.6321 * Real.log 2.5024 - 4.6484 * 2.5024 from rfl]` or `unfold pinchF`. Use `rw [pinchF]`? — that IS the standard way for defs... The error might be that after my Edit, pinchF is defined and the rw [pinchF] at pinchF_at_critical — hmm — actually "equation theorems for pinchF" — the def's equational lemmas — for a simple def there's `pinchF.eq_def` or the auto-generated equation — rw [pinchF] uses those ✓ normally works. Let me use `unfold pinchF` instead? or `simp only [pinchF]`. I'll try `rw [show pinchF 2.5024 = _ from rfl]`? — the rfl show: `show pinchF 2.5024 = 11.6321 * Real.log 2.5024 - 4.6484 * 2.5024 from rfl` — wait rfl requires the body to be DEFEQ — it is ✓. Let me use that form for pinchF_at_critical and pinchF'_at_critical, and for h6 : pinchF L = ... := rfl (that one worked — it's a term-level rfl ✓).
Hmm — actually maybe the issue is `rw [pinchF]` inside pinchF_at_critical where the goal has `pinchF 2.5024 ≤ -0.96203`: rw [pinchF] unfolds ALL pinchF occurrences ✓ should work — "Failed to rewrite using equation theorems for `pinchF`" — the equation-theorem generation for `def pinchF (L : ℝ) : ℝ := ...` — Lean 4 auto-generates `pinchF.eq_1`? — for non-pattern-matching defs, `rw [pinchF]` should use `pinchF.eq_def`. Hmm — maybe the def's generated equation is named differently and rw [pinchF] needs `pinchF.eq_def`?? For simple defs, `rw [pinchF]` works (I've seen it). Let me test with `unfold pinchF`.
5. Line 3998: pinchF'_at_critical's `rw [div_le_iff₀ ...]` — div_le_iff₀'s pattern `?m/2.5024 ≤ ?m` not found in `11.6321 / 2.5024 ≤ 4.6484` — div_le_iff₀ (hc : 0 < c) : a / c ≤ b ↔ a ≤ b * c — with c = 2.5024, a = 11.6321, b = 4.6484: pattern a/c ≤ b ✓ should match... The error shows the pattern `?m.47 / 2.5024 ≤ ?m.46` — matches 11.6321/2.5024 ≤ 4.6484 ✓ should fire! Unless div_le_iff₀'s form is different (like the earlier div_le_div_of_nonneg_left swap issue). Let me check div_le_iff₀'s signature.
6. Line 4030: linarith at the hbound's h1 (x in Ici (log 12)) — the `by linarith [hx.1, hcase, hL] : x ∈ Set.Ici (Real.log 12)` — membership form: x ∈ Ici (log 12) ⟺ log 12 ≤ x: from hx.1 : 2.5024 ≤ x and hL : log 12 ≤ L and hcase : 2.5024 ≤ L: log 12 ≤ 2.5024?? — log 12 = 2.4849 ≤ 2.5024 ✓ — linarith needs log_twelve_ge (2.4848 ≤ log 12) to bridge: log 12 ≥ 2.4848 and I need log 12 ≤ 2.5024 — NO relation between log 12 and 2.5024 in context!! log 12's actual value 2.4849 ≤ 2.5024 — I need `Real.log 12 ≤ 2.5024` — from log 12 ≤ log 2.5024·... or log 12 ≤ 2.4849·... — hmm: log 12 ≈ 2.4849: prove log 12 ≤ 2.5024 via log 12 ≤ 2.5-ish: 12 ≤ e^2.5024?? e^2.5024 ≥ 12 ⟺ log 12 ≤ 2.5024: e^2.5024 ≈ 12.211 ≥ 12 ✓ — another exp-lower (partial sums: e^2.5024 = e²·e^0.5024: e^0.5024 ≥ Σ_{k<7}: 1+0.5024+0.126203+0.021137+0.002655+0.000267 = 1.652662: 7.3890566·1.652662 = 12.2114 ≥ 12 ✓). OR simpler: log 12 ≤ 2.5024 via log 12 = 4 log 2 − log(4/3) ≤ 4·0.6931472+0 = 2.7726 ✗ too big; log 12 = 2 log 2 + log 3 ≤ 2·0.69315+1.0987 = 2.485 ✗ — need log 3 ≤ 1.0987: 3 ≥ e^1.0987?? no — log 3 ≤ 1.0987 ⟺ 3 ≤ e^1.0987: e^1.0987 ≥ 3: partial sums e^1.0987 = e·e^0.0987 ≥ 2.7182818·1.10374 = 3.00015 ≥ 3 ✓ (e^0.0987 ≥ Σ_{k<6} = 1+0.0987+0.004871+0.000160+0.000004 = 1.103735): 2.7182818·1.103735 = 3.00016 ≥ 3 ✓. So log 3 ≤ 1.0987 and log 12 ≤ 2·0.69315+1.0987 = 2.4850 ≤ 2.5024 ✓ (via log_two_lt_d9: log 2 < 0.6931471809 ≤ 0.69315 ✓). Add a lemma `log_twelve_le : Real.log 12 ≤ 2.5024`.
Let me apply all these fixes:
- exp_point4848_le: DELETE (wrong direction) — replace log_twelve_ge with the 4·log 2 − log(4/3) route + the 4-term neg_log lemma.
- Add neg_log_one_sub_le_four.
- Add log_twelve_le (for the pinch's Ici memberships — needed in both branches: x ∈ Ici (log 12) needs log 12 ≤ x: from 2.5024 ≤ x or L ≥ log 12 ✓ the second is fine; but the first branch's `hanti (2.5024 ∈ Ici (log 12))` needs log 12 ≤ 2.5024 ✓ via log_twelve_le; and x ∈ Ici (log 12) from 2.5024 ≤ x needs log 12 ≤ 2.5024 ✓).
- h5 ascription fix.
- pinchF unfold issues: use show-rfl forms.
- div_le_iff₀ signature check.
Several issues. Checking `div_le_iff₀` signature, then fixing all.
tool: Bash
input
{
"command": "grep -rn \"theorem div_le_iff\u2080\\b\\|lemma div_le_iff\u2080\\b\" D:/Python/Quantum/zeta-23-lean/.lake/packages/mathlib/Mathlib/ --include=\"*.lean\" 2>/dev/null | head -3",
"description": "Check div_le_iff\u2080 signature"
}
raw content_json (database row)
[{"type":"thinking","thinking":"1. Line 3918: exp_point4848_le — the norm_num at h left `7743114841069643681 / 4768371582031250000 ≤ Real.exp (303/625)` and a✝ : 1.6239 < Real.exp 0.4848 — the partial sum didn't reach 1.6239?! Σ_{k<7} 0.4848^k/k! = 1.623851 — hmm — the norm_num normalized the sum to the giant rational `7743114841069643681/4768371582031250000` — let me compute: 7743114841069643681/4768371582031250000 = 1.62385·... = 1.623846. And 1.6239 — the target Real.exp 0.4848 ≤ 1.6239 needs the partial sum ≥ 1.6239?? NO — the partial sum is a LOWER bound for exp: Σ_{k<7} = 1.623846 ≤ e^0.4848 — and I want e^0.4848 ≤ 1.6239 — the partial sum doesn't prove THAT (it's a lower bound on exp, giving exp ≥ 1.623846 — useless for an upper bound!!). WAIT — Real.sum_le_exp_of_nonneg : Σ_{k<n} x^k/k! ≤ exp x — LOWER bound on exp ✓. For exp UPPER bounds I used this for e^0.571 ≥ 23/13 etc. (lower-bound-the-exp then compare). Here I want e^0.4848 ≤ 1.6239 (UPPER) — sum_le_exp gives exp ≥ 1.623846 — WRONG DIRECTION for my lemma!! \n\nHold on — how did the earlier exp-upper lemmas work? E.g. log_23_13_le : log(23/13) ≤ 0.571 via 23/13 ≤ e^0.571: partial sums give e^0.571 ≥ Σ ≥ 1.769 ≥ 23/13 ✓ — there I needed e^U ≥ x (exp LOWER bound ✓ sum_le_exp works). For log_twelve_ge I need e^2.4848 ≤ 12 (exp UPPER) — sum_le_exp gives exp LOWER ✗. Hmm — but I DID use this pattern for e^2.5 ≤ 13 in §13 (exp_two_point_five_le_thirteen): via e^0.5 ≤ 1.6488 — and e^0.5 ≤ 1.6488 was proven via le_of_pow_le_pow_left₀ ((e^0.5)² ≤ 1.6488² ⟸ e ≤ 1.6488²)!! The squaring trick. For e^0.4848 ≤ 1.6239: (e^0.4848)² = e^0.9696 ≤ 1.6239² = 2.63705121 ⟸ e^0.9696 ≤ 2.63705121: e^0.9696 = e/e^0.0304 = 2.7182819/1.03087·... = 2.63691·... ≤ 2.63705 ✓ — via e^0.9696 ≤ ?: e^0.9696 ≤ 2.6371: partial sums give LOWER 2.6368-ish ✗ again (need upper). ARGH — exp upper bounds need: e^x ≤ U ⟺ 1 ≤ U·e^{−x} ⟺ e^{−x} ≥ 1/U — and e^{−x} ≥ 1−x+x²/2−x³/6 (alternating LOWER bound for x ≥ 0? e^{−x} ≥ 1−x for sure; better: e^{−x} ≥ 1−x+x²/2−x³/6 for x ≥ 0?? — the alternating stops: e^{−x} = Σ(−x)^k/k!: for x ≥ 0, the series alternates with decreasing terms after k > x: the odd-stops are LOWER bounds ✓ (Taylor with remainder: e^{−x} = T_{2m+1}(x) + e^{−ξ}x^{2m+2}/(2m+2)! ≥ T_{2m+1} since the remainder term is +). So e^{−x} ≥ 1−x+x²/2−x³/6 (k≤3, odd stop) for x ≥ 0 ✓. For x = 0.4848: e^{−0.4848} ≥ 1−0.4848+0.117516−0.018992 = 0.613724. Then e^0.4848 ≤ 1/0.613724 = 1.629415 ✗ > 1.6239. k≤5: e^{−0.4848} ≥ 1−0.4848+0.117516−0.018992+0.002302−0.000223 = 0.615803: 1/0.615803 = 1.62391·... = 1.623906 ✗ barely > 1.6239!! k≤7: +0.0000180−0.00000125 = 0.615820: 1/0.615820 = 1.623862 ≤ 1.6239 ✓. So e^0.4848 ≤ 1/0.615820·... ≤ 1.6239 via e^{−0.4848} ≥ 0.615820 (k≤7 alternating). Hmm — that's a tight 3.8e-5 margin. The alternating lower bound: e^{−x} ≥ Σ_{k≤2m+1}(−x)^k/k! — is that a clean Mathlib lemma? `Real.sum_le_exp_of_nonneg` is for positive x. For e^{−x}: exp(−x) = exp((−x)) — sum_le_exp_of_nonneg needs x ≥ 0 (the terms are positive for its use in bounds). For the alternating case I'd prove it via `Real.exp_bound'`? or via the inequality e^{-x} ≥ 1−x (Real.add_one_le_exp: 1+z ≤ e^z for all z ✓ `Real.add_one_le_exp : 1 + x ≤ exp x` for ALL x!). So e^{−0.4848} ≥ 1−0.4848 = 0.5152: e^0.4848 ≤ 1/0.5152 = 1.9410 ✗ too weak.\n\nAlternative for log 12 ≥ 2.4848: use log 12 = log 3 + log 4 = log 3 + 2 log 2 ≥ 1.0986 + 2·0.6931471 = 1.0986+1.3862942 = 2.4848942 ≥ 2.4848 ✓!! With log 3 ≥ 1.0986 (13... log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986: e^1.0986 = 2.99991·... ≤ 3 ✓ — again exp upper — sum_le_exp gives lower 2.99986·... need ≥ 3?? e^1.0986 ≥ 3 needed for log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986 — exp upper again!!). Hmm — but wait — log 3: I have log_thirteen_le (log 13 ≤ 2.565) and earlier in the file `hlog3 : Real.log 3 ≤ 1.1` (in dirichletC2_le_one's proof) and `hlog3 : (1:ℝ) ≤ Real.log 3` (antitoneOn_log_div_sq's proof: log 3 ≥ 1 via e ≤ 3 ✓ — that's the EASY direction: log 3 ≥ 1 ⟺ 3 ≥ e ✓ exp_one_lt_d9 ✓). For log 3 ≥ 1.0986: 3 ≥ e^1.0986 — e^1.0986 = e·e^0.0986 ≤ 2.7182819·1.10363 = 2.99999·... — e^0.0986 ≤ 1.10363: partial sums give LOWER 1.1035-ish ✗ upper needed — via (e^0.0986)² = e^0.1972 ≤ 1.10363² = 1.217999·... ⟸ e^0.1972 ≤ 1.217999: partial sums LOWER 1.21793 ✗ upper... e^0.1972 ≤ 1/(1−0.1972) = 1.24579 ✗; ≤ 1/(1−0.0986)² = 1.23167 ✗; e^0.1972 = 1.21794 — sum gives lower ~1.21791, need upper ≤ 1.217999: via e^{−0.1972} ≥ 1−0.1972+0.019444−0.001278 = 0.820966: 1/0.820966 = 1.218078 ✗ > 1.217999. k≤5: +0.000063−0.0000025 = 0.821026: 1/1.218006 ✗ still. ARGH.\n\nSTOP. The clean way for log 12 ≥ 2.4848: log 12 = log(4·3) = 2·log 2 + log 3 with log 3 ≥ 1.0986. For log 3 ≥ 1.0986 — how about log 3 ≥ 1.0986 ⟺ 3 ≥ e^1.0986: e^1.0986 ≤ 3 — via e^1.0986 = (e^{1.0986/2})² ≤ (partial-upper?)... \n\nOK here's the CLEAN general trick for exp upper bounds I should have used all along: e^x ≤ 1/(1−x) for 0 ≤ x < 1 (from e^{−x} ≥ 1−x: 1−x ≤ e^{−x} ⟹ e^x ≤ 1/(1−x) ✓ Real.add_one_le_exp gives 1+(−x) ≤ e^{−x} ✓). And e^x = (e^{x/n})ⁿ ≤ 1/(1−x/n)ⁿ. For e^0.4848: n = 4: e^0.4848 ≤ 1/(1−0.1212)⁴ = 1/0.8788⁴: 0.8788² = 0.772289; ⁴ = 0.596431: 1/0.596431 = 1.676645 ✗ > 1.6239. n = 8: 0.4848/8 = 0.0606: 1/(1−0.0606)⁸ = 1/0.9394⁸: 0.9394² = 0.882472; ⁴ = 0.778757; ⁸ = 0.606462: 1/0.606462 = 1.648911 ✗. n = 16: 0.0303: 1/(1−0.0303)¹⁶: 0.9697^16 = e^{16·ln 0.9697} = e^{16·(−0.030768)} = e^{−0.492291} = 0.611220: 1/0.611220 = 1.636078 ✗. The 1/(1−x/n)ⁿ route converges to e^x from above but slowly (like the earlier computations). True e^0.4848 = 1.623809·... — so even 1.6239 IS close to the true value (margin 9e-5) — the alternating-remainder route (k≤7) reached 1.623862 ✓ barely.\n\nFor log 3 ≥ 1.0986 (needed for log 12 via 2·log 2+log 3): true log 3 = 1.0986123 — need lower bound ≥ 1.0986 (margin 1.2e-5!). Via the LOG-SERIES at a rational: log 3 = log(e·(3/e)) = 1 + log(3/e): 3/e = 1.103639: log(1.103639) = log(1+x), x = 0.103639: log(1+x) ≥ x−x²/2+x³/3−x⁴/4 (my log_one_add_ge!): 0.103639−0.005371+0.000371−0.000029 = 0.098610·... = 0.0986104. log 3 ≥ 1+0.0986104 = 1.0986104 ≥ 1.0986 ✓ (margin 1.04e-5 — TIGHT but exact ✓ — with x = 3/e−1: need x ≤ 0.10364 (rational upper: 3/e ≤ 3/2.7182818 = 1.1036395·... ⟹ x = 3/e−1 ≤ 0.1036395 — use 0.10364 as the rational x-bound: log(1+x) ≥ log(1+0.1036395·...)?? — log increasing: log(3/e) = log(1+x) with x = 3/e−1: I need a LOWER bound on log(1+x) — the alternating bound is increasing in x, so I need x ≥ x₀: x = 3/e−1 ≥ 3/2.7182819−1 = 0.1036388·... — with e ≤ 2.7182819: 3/e ≥ 3/2.7182819 = 1.10363881·... ⟹ x ≥ 0.10363881. Then log(1+x) ≥ x−x²/2+x³/3−x⁴/4 evaluated at x ≥ 0.10363881 — the alternating poly p(x) = x−x²/2+x³/3−x⁴/4 is INCREASING for x ∈ [0,1]? p′(x) = 1−x+x²−x³ > 0 ✓ (1−x+x²−x³ = (1−x)+x²(1−x) = (1−x)(1+x²) ≥ 0 for x ≤ 1 ✓). So p(x) ≥ p(0.10363881) — but the bound p(x) ≤ log(1+x) holds for all x ≥ 0 (log_one_add_ge) — so log(1+x) ≥ p(x) ≥ p(0.10363881) (p increasing — PROVE p increasing? or just: log(1+x) ≥ p(x) and p(x) ≥ p(x₀) needs monotonicity of p — ugh. SIMPLER: use the LARGER rational x₀ = 0.10363 with log(1+x) ≥ p(x) — NO WAIT — the bound log(1+x) ≥ p(x) holds at the ACTUAL x = 3/e−1 (whatever it is) — and x ≥ 0.10363 ⟹ p(x) ≥ p(0.10363) if p is increasing. p(0.10363) = 0.10363−0.0053696+0.0003709−0.0000288 = 0.0986025. log 3 ≥ 1.0986025 ≥ 1.0986 ✓ (margin 2.5e-6 — TOO TIGHT!). Hmm — p(x) at the true x = 0.10363881: 0.10363881−0.00537049+0.00037125−0.00002886 = 0.09861071 — so log 3 ≥ 1.09861071. The margin over 1.0986 is 1.07e-5. To prove p increasing on [0.10363, x]: p′(x) = (1−x)(1+x²) ≥ 0 ✓ for x ≤ 1 — formalize via antitoneOf/MonotoneOn-of-deriv-nonneg (the antitoneOn_of_deriv_nonpos pattern has a monotone sibling: monotoneOn_of_deriv_nonneg ✓ exists presumably).\n Then log 12 = 2·log 2 + log 3 ≥ 2·0.6931471+1.0986 = 2.4848942·... wait — use the EXACT lower bounds: log 2 ≥ 0.6931471 (log_two_gt_d9) and log 3 ≥ 1+0.09861071·... — with the p-increasing subtlety: log(1+x) ≥ p(x) at x = 3/e−1 — and x ≥ 3/2.7182819 − 1 — compute p(3/2.7182819−1) EXACTLY as a rational: x₀ = 3/2.7182819 − 1 = 0.10363883·... — p(x₀) as a rational number: x₀ = 3/2.7182819−1 — p(x₀) = x₀−x₀²/2+x₀³/3−x₀⁴/4 — norm_num can compute this with x₀ = (3/2.7182819 − 1) — the division inside — norm_num handles divisions of literals ✓. Then log 3 ≥ 1+p(x₀)?? — NO — the bound is log(1+x) ≥ p(x) with x = 3/e−1, and p increasing ⟹ p(x) ≥ p(x₀) since x ≥ x₀ (e ≤ 2.7182819 ⟹ 3/e ≥ 3/2.7182819 = x₀+1 ⟹ x ≥ x₀ ✓). So log 3 ≥ 1 + p(x₀) with p increasing on [x₀, x] — need x ≤ 1 for p′ ≥ 0 ✓ (x ≤ 0.11 ≤ 1 ✓).\n Hmm — p increasing on [0, 1.1] needs the monotoneOn_of_deriv_nonneg proof (~30 lines). Fine.\n log 12 ≥ 2·0.6931471 + (1+p(x₀)) with p(x₀) = norm_num-computed ≈ 0.09861071: total ≥ 1.3862942+1.09861071 = 2.48490491 ≥ 2.4848 ✓ (margin 1.05e-4 ✓).\n\nHmm — this is getting heavy. ALTERNATIVE much simpler: log 12 ≥ 2.4848 ⟺ 12 ≥ e^2.4848 ⟺ 12⁴ ≥ e^{9.9392}·... no. ⟺ log 12 ≥ 2.4848 ⟸ log 12 = log(16·0.75) = 4 log 2 + log(3/4) = 4·0.6931471 + log 0.75: log 0.75 = −log(4/3) ≥ −(1/3) (log z ≤ z−1: log(4/3) ≤ 1/3 = 0.333333): log 12 ≥ 2.7725887−0.3333334 = 2.4392553 ✗ < 2.4848. Better: log(4/3) ≤ (4/3−1)·... or the finer: log(4/3) = −log(3/4): −log(1−y), y = 1/4: −log(1−1/4) ≤ y+y²/2+y³/(3(1−y)) = 0.25+0.03125+0.015625/(3·0.75 = 2.25) = 0.25+0.03125+0.006944 = 0.288194. log 12 ≥ 2.7725887−0.288194 = 2.4843947 ✗ < 2.4848 (by 4e-4!). One more term: y+y²/2+y³/3+y⁴/(4(1−y)) = 0.25+0.03125+0.005208+0.000651/1 = 0.287109·... wait my neg_log_one_sub_le only has 3 terms. Extend? log(4/3) ≤ 0.287109+0.000651 = 0.287760?? hmm — recompute: −log(1−y) = y + y²/2 + y³/3 + y⁴/4·(1/(1−y))·... — with the 3-term bound (y+y²/2+y³/(3(1−y))): 0.25+0.03125+0.015625/2.25 = 0.288194. The TRUE log(4/3) = 0.287682. log 12 = 4·0.6931471−0.288194·... hmm wait — log 12 = 4 log 2 − log(4/3)?? log 12 = log(16·(12/16)) = 4 log 2 + log(3/4) = 4 log 2 − log(4/3) ✓ ≥ 2.7725887 − 0.288194 = 2.4843947 ✗ short by 4e-4. With a 4-term bound (y+y²/2+y³/3+y⁴/(4(1−y))): 0.25+0.03125+0.005208+0.000651 = 0.287109·... hmm that's LESS than the 3-term (0.288194)? The 4-term: y³/3 = 0.005208 (vs y³/(3(1−y)) = 0.006944) + y⁴/(4(1−y)) = 0.00390625/3 = 0.001302·... 0.25+0.03125+0.005208+0.001302 = 0.28776. Still ≥ true 0.287682 ✓: log 12 ≥ 2.7725887−0.287760 = 2.4848287 ≥ 2.4848 ✓ (margin 2.87e-5 — tight but exact ✓). Requires a 4-term version of neg_log_one_sub_le: −log(1−y) ≤ y+y²/2+y³/3+y⁴/(4(1−y)) via 1/(1−t) ≤ 1+t+t²+t³/(1−y) on [0,y] — same integral machine (1 ≤ (1−t)(1+t+t²+t³/(1−y)) = 1−t³+t³(1−t)/(1−y) ⟺ t³ ≤ t³(1−t)/(1−y) ⟺ 1−y ≤ 1−t ⟺ t ≤ y ✓). EASY extension.\n\nSo plan for log_twelve_ge: log 12 = 4·log 2 − log(4/3) ≥ 4·0.6931471 − 0.287760 = 2.4848287 ≥ 2.4848 ✓ with the 4-term neg_log bound: log(4/3) = −log(3/4) = −log(1−1/4) ≤ 1/4+1/32+1/192+1/(1024·(4·(3/4)))·... compute: y = 1/4: y+y²/2+y³/3+y⁴/(4(1−y)) = 0.25+0.03125+0.005208333+0.00390625/3 = 0.25+0.03125+0.005208333+0.001302083 = 0.287760416 ≤ 0.28777 ✓ (margin 1e-5). Then log 12 ≥ 4·0.6931471−0.28777 = 2.7725884−0.28777 = 2.4848184·... hmm — 4·0.6931471 = 2.7725884: −0.28777 = 2.4848184 ≥ 2.4848 ✓ (margin 1.84e-5). Use the sharper internal: 2.7725884−0.287760416 = 2.484827984 ✓.\n\nAnd log 4/3 = −log(3/4): −log(3/4) = −log(1−1/4) — the 4-term lemma: `neg_log_one_sub_le_four : 0 ≤ y → y < 1 → -Real.log (1-y) ≤ y + y^2/2 + y^3/3 + y^4/(4*(1-y))`.\n\nFor log_2_5024_le (log 2.5024 ≤ 0.9173): e^0.9173 ≥ 2.5024 — sum_le_exp partial sums ✓ (worked — my partial sum computed 2.50251073 ≥ 2.5024 ✓ — the norm_num at h in that proof should verify Σ ≥ 2.5024: the norm_num reduced h to the giant rational `... ≤ Real.exp (303/625)`?? — 0.9173 = 303/625?? — 303/625 = 0.4848!! — the error at 3918 was about exp (303/625) = exp 0.4848 — that was exp_point4848_le's failure (wrong direction). The log_2_5024 proof used e^0.9173 with partial sums — that's the CORRECT direction (exp lower) ✓ keep it.\n\n2. Line 3936: `Real.le_log_iff_exp_le ?m.165 12` — le_log_iff_exp_le's signature: `Real.le_log_iff_exp_le (hx : 0 < x) : a ≤ Real.log x ↔ Real.exp a ≤ x` — it takes the POINT x as an EXPLICIT/implicit arg and a as implicit: `Real.le_log_iff_exp_le (hx : 0 < x) : a ≤ log x ↔ exp a ≤ x` — so `Real.le_log_iff_exp_le (show (0:ℝ) < 12 by norm_num)` : a ≤ log 12 ↔ exp a ≤ 12 — then `.mp`?? I want 2.4848 ≤ log 12 ⟸ exp 2.4848 ≤ 12: (le_log_iff_exp_le).mpr h1? or rw [h5]: the goal `2.4848 ≤ Real.log 12` — rw [Real.le_log_iff_exp_le (0<12)] turns it into Real.exp 2.4848 ≤ 12 = h1 ✓ — but the error shows the implicit ?m.165 unresolved — because rw [h5] with h5 := Real.le_log_iff_exp_le (...) — the `a` in the iff is a METAVAR — rw [h5] rewrites `?a ≤ Real.log 12` — the goal has 2.4848 ≤ log 12 ✓ should unify ?a := 2.4848 — the error \"don't know how to synthesize implicit argument x\" — x is the POINT (12 here) — the implicit x in le_log_iff_exp_le is the point?! Signature: `Real.le_log_iff_exp_le {a : ℝ} {x : ℝ} (hx : 0 < x) : a ≤ Real.log x ↔ Real.exp a ≤ x` — x implicit (from hx). My h5 := Real.le_log_iff_exp_le (by norm_num : (0:ℝ) < 12) ✓ determines x = 12. Then `rw [h5]` — h5 is an IFF — rw with an iff rewrites `a ≤ Real.log 12 ↔ ...` — the goal `2.4848 ≤ Real.log 12` — the iff's LHS is `?a ≤ Real.log 12` ✓ unifies ✓... The error \"don't know how to synthesize implicit argument x\" — maybe the `by norm_num : (0:ℝ) < 12` ascription issue again (the `:` binding). Use (show (0:ℝ) < 12 by norm_num).\n\n3. Line 3921: the goal `2.4848 ≤ Real.log 12` unsolved — cascade of the h5 issue: after rw [h5] failed... restructure:\n```\n have h5 : (2.4848 : ℝ) ≤ Real.log 12 := by\n rw [Real.le_log_iff_exp_le (show (0 : ℝ) < 12 by norm_num)]\n exact h1\n exact h5\n```\nOr directly: exact (Real.le_log_iff_exp_le (show (0:ℝ) < 12 by norm_num)).mpr h1.\n\n4. Line 3964: \"Failed to rewrite using equation theorems for pinchF\" — rw [pinchF] on a private def failed?? — I made pinchF/pinchF' `private def` — private defs can't be unfolded by rw from outside?? — I changed them to plain `def` in the final edit (checked: the Edit I applied has `def pinchF` and `def pinchF'` — line 3964's error is at `rw [pinchF]` in pinchF_at_critical — \"Failed to rewrite using equation theorems\" — the def unfolding: rw [pinchF] unfolds the def via its equation — for a plain def this should work... unless pinchF is a def with an explicit argument pattern: `def pinchF (L : ℝ) : ℝ := 11.6321 * Real.log L - 4.6484 * L` — rw [pinchF] rewrites `pinchF 2.5024` → the body ✓ should work. \"Failed to rewrite using equation theorems\" — hmm — maybe the issue is the `def` needs the unfold lemma: use `rw [show pinchF 2.5024 = 11.6321 * Real.log 2.5024 - 4.6484 * 2.5024 from rfl]` or `unfold pinchF`. Use `rw [pinchF]`? — that IS the standard way for defs... The error might be that after my Edit, pinchF is defined and the rw [pinchF] at pinchF_at_critical — hmm — actually \"equation theorems for pinchF\" — the def's equational lemmas — for a simple def there's `pinchF.eq_def` or the auto-generated equation — rw [pinchF] uses those ✓ normally works. Let me use `unfold pinchF` instead? or `simp only [pinchF]`. I'll try `rw [show pinchF 2.5024 = _ from rfl]`? — the rfl show: `show pinchF 2.5024 = 11.6321 * Real.log 2.5024 - 4.6484 * 2.5024 from rfl` — wait rfl requires the body to be DEFEQ — it is ✓. Let me use that form for pinchF_at_critical and pinchF'_at_critical, and for h6 : pinchF L = ... := rfl (that one worked — it's a term-level rfl ✓).\n\nHmm — actually maybe the issue is `rw [pinchF]` inside pinchF_at_critical where the goal has `pinchF 2.5024 ≤ -0.96203`: rw [pinchF] unfolds ALL pinchF occurrences ✓ should work — \"Failed to rewrite using equation theorems for `pinchF`\" — the equation-theorem generation for `def pinchF (L : ℝ) : ℝ := ...` — Lean 4 auto-generates `pinchF.eq_1`? — for non-pattern-matching defs, `rw [pinchF]` should use `pinchF.eq_def`. Hmm — maybe the def's generated equation is named differently and rw [pinchF] needs `pinchF.eq_def`?? For simple defs, `rw [pinchF]` works (I've seen it). Let me test with `unfold pinchF`.\n\n5. Line 3998: pinchF'_at_critical's `rw [div_le_iff₀ ...]` — div_le_iff₀'s pattern `?m/2.5024 ≤ ?m` not found in `11.6321 / 2.5024 ≤ 4.6484` — div_le_iff₀ (hc : 0 < c) : a / c ≤ b ↔ a ≤ b * c — with c = 2.5024, a = 11.6321, b = 4.6484: pattern a/c ≤ b ✓ should match... The error shows the pattern `?m.47 / 2.5024 ≤ ?m.46` — matches 11.6321/2.5024 ≤ 4.6484 ✓ should fire! Unless div_le_iff₀'s form is different (like the earlier div_le_div_of_nonneg_left swap issue). Let me check div_le_iff₀'s signature.\n\n6. Line 4030: linarith at the hbound's h1 (x in Ici (log 12)) — the `by linarith [hx.1, hcase, hL] : x ∈ Set.Ici (Real.log 12)` — membership form: x ∈ Ici (log 12) ⟺ log 12 ≤ x: from hx.1 : 2.5024 ≤ x and hL : log 12 ≤ L and hcase : 2.5024 ≤ L: log 12 ≤ 2.5024?? — log 12 = 2.4849 ≤ 2.5024 ✓ — linarith needs log_twelve_ge (2.4848 ≤ log 12) to bridge: log 12 ≥ 2.4848 and I need log 12 ≤ 2.5024 — NO relation between log 12 and 2.5024 in context!! log 12's actual value 2.4849 ≤ 2.5024 — I need `Real.log 12 ≤ 2.5024` — from log 12 ≤ log 2.5024·... or log 12 ≤ 2.4849·... — hmm: log 12 ≈ 2.4849: prove log 12 ≤ 2.5024 via log 12 ≤ 2.5-ish: 12 ≤ e^2.5024?? e^2.5024 ≥ 12 ⟺ log 12 ≤ 2.5024: e^2.5024 ≈ 12.211 ≥ 12 ✓ — another exp-lower (partial sums: e^2.5024 = e²·e^0.5024: e^0.5024 ≥ Σ_{k<7}: 1+0.5024+0.126203+0.021137+0.002655+0.000267 = 1.652662: 7.3890566·1.652662 = 12.2114 ≥ 12 ✓). OR simpler: log 12 ≤ 2.5024 via log 12 = 4 log 2 − log(4/3) ≤ 4·0.6931472+0 = 2.7726 ✗ too big; log 12 = 2 log 2 + log 3 ≤ 2·0.69315+1.0987 = 2.485 ✗ — need log 3 ≤ 1.0987: 3 ≥ e^1.0987?? no — log 3 ≤ 1.0987 ⟺ 3 ≤ e^1.0987: e^1.0987 ≥ 3: partial sums e^1.0987 = e·e^0.0987 ≥ 2.7182818·1.10374 = 3.00015 ≥ 3 ✓ (e^0.0987 ≥ Σ_{k<6} = 1+0.0987+0.004871+0.000160+0.000004 = 1.103735): 2.7182818·1.103735 = 3.00016 ≥ 3 ✓. So log 3 ≤ 1.0987 and log 12 ≤ 2·0.69315+1.0987 = 2.4850 ≤ 2.5024 ✓ (via log_two_lt_d9: log 2 < 0.6931471809 ≤ 0.69315 ✓). Add a lemma `log_twelve_le : Real.log 12 ≤ 2.5024`.\n\nLet me apply all these fixes:\n- exp_point4848_le: DELETE (wrong direction) — replace log_twelve_ge with the 4·log 2 − log(4/3) route + the 4-term neg_log lemma.\n- Add neg_log_one_sub_le_four.\n- Add log_twelve_le (for the pinch's Ici memberships — needed in both branches: x ∈ Ici (log 12) needs log 12 ≤ x: from 2.5024 ≤ x or L ≥ log 12 ✓ the second is fine; but the first branch's `hanti (2.5024 ∈ Ici (log 12))` needs log 12 ≤ 2.5024 ✓ via log_twelve_le; and x ∈ Ici (log 12) from 2.5024 ≤ x needs log 12 ≤ 2.5024 ✓).\n- h5 ascription fix.\n- pinchF unfold issues: use show-rfl forms.\n- div_le_iff₀ signature check.","signature":""},{"type":"text","text":"Several issues. Checking `div_le_iff₀` signature, then fixing all."},{"type":"tool_use","id":"Bash_281","name":"Bash","input":{"command":"grep -rn \"theorem div_le_iff₀\\b\\|lemma div_le_iff₀\\b\" D:/Python/Quantum/zeta-23-lean/.lake/packages/mathlib/Mathlib/ --include=\"*.lean\" 2>/dev/null | head -3","description":"Check div_le_iff₀ signature"},"extra_content":null}]