mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

@@ -47,7 +47,7 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   have hnat₁ : p ∣ n ^ 2 + 1 := by
     refine' int.coe_nat_dvd.mp _
     simp only [Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, int.coe_nat_dvd.mp]
-    refine' (ZMod.int_cast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
+    refine' (ZMod.intCast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
     simp only [Int.cast_pow, Int.cast_add, Int.cast_one, ZMod.coe_valMinAbs]
     rw [pow_two, ← hy]; exact add_left_neg 1
   have hnat₂ : n ≤ p / 2 := ZMod.natAbs_valMinAbs_le y

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

@@ -67,11 +67,11 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   have hreal₃ : (k : ℝ) ^ 2 + 4 ≥ p := by assumption_mod_cast
   have hreal₅ : (k : ℝ) > 4 :=
     by
-    refine' lt_of_pow_lt_pow 2 k.cast_nonneg _
+    refine' lt_of_pow_lt_pow_left 2 k.cast_nonneg _
     linarith only [hreal₂, hreal₃]
   have hreal₆ : (k : ℝ) > sqrt (2 * n) :=
     by
-    refine' lt_of_pow_lt_pow 2 k.cast_nonneg _
+    refine' lt_of_pow_lt_pow_left 2 k.cast_nonneg _
     rw [sq_sqrt (mul_nonneg zero_le_two n.cast_nonneg)]
     linarith only [hreal₁, hreal₃, hreal₅]
   exact ⟨n, hnat₁, by linarith only [hreal₆, hreal₁]⟩

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce64cd319bb6b3e82f31c2d38e79080d377be451

@@ -3,12 +3,12 @@ Copyright (c) 2021 Manuel Candales. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
 -/
-import Mathbin.Data.Real.Basic
-import Mathbin.Data.Real.Sqrt
-import Mathbin.Data.Nat.Prime
-import Mathbin.NumberTheory.PrimesCongruentOne
-import Mathbin.NumberTheory.LegendreSymbol.QuadraticReciprocity
-import Mathbin.Tactic.LinearCombination
+import Data.Real.Basic
+import Data.Real.Sqrt
+import Data.Nat.Prime
+import NumberTheory.PrimesCongruentOne
+import NumberTheory.LegendreSymbol.QuadraticReciprocity
+import Tactic.LinearCombination
 
 #align_import imo.imo2008_q3 from "leanprover-community/mathlib"@"08b081ea92d80e3a41f899eea36ef6d56e0f1db0"
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/63721b2c3eba6c325ecf8ae8cca27155a4f6306f

@@ -56,7 +56,7 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   have hnat₅ : p ∣ k ^ 2 + 4 := by
     cases' hnat₁ with x hx
     have : (p : ℤ) ∣ k ^ 2 + 4 := by
-      use (p : ℤ) - 4 * n + 4 * x
+      use(p : ℤ) - 4 * n + 4 * x
       have hcast₁ : (k : ℤ) = p - 2 * n := by assumption_mod_cast
       have hcast₂ : (n : ℤ) ^ 2 + 1 = p * x := by assumption_mod_cast
       linear_combination ((k : ℤ) + p - 2 * n) * hcast₁ + 4 * hcast₂

mathlib commit https://github.com/leanprover-community/mathlib/commit/8ea5598db6caeddde6cb734aa179cc2408dbd345

@@ -2,11 +2,6 @@
 Copyright (c) 2021 Manuel Candales. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
-
-! This file was ported from Lean 3 source module imo.imo2008_q3
-! leanprover-community/mathlib commit 08b081ea92d80e3a41f899eea36ef6d56e0f1db0
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Data.Real.Basic
 import Mathbin.Data.Real.Sqrt
@@ -15,6 +10,8 @@ import Mathbin.NumberTheory.PrimesCongruentOne
 import Mathbin.NumberTheory.LegendreSymbol.QuadraticReciprocity
 import Mathbin.Tactic.LinearCombination
 
+#align_import imo.imo2008_q3 from "leanprover-community/mathlib"@"08b081ea92d80e3a41f899eea36ef6d56e0f1db0"
+
 /-!
 # IMO 2008 Q3
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/bf2428c9486c407ca38b5b3fb10b87dad0bc99fa

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
 
 ! This file was ported from Lean 3 source module imo.imo2008_q3
-! leanprover-community/mathlib commit 308826471968962c6b59c7ff82a22757386603e3
+! leanprover-community/mathlib commit 08b081ea92d80e3a41f899eea36ef6d56e0f1db0
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -17,6 +17,9 @@ import Mathbin.Tactic.LinearCombination
 
 /-!
 # IMO 2008 Q3
+
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
 Prove that there exist infinitely many positive integers `n` such that `n^2 + 1` has a prime
 divisor which is greater than `2n + √(2n)`.
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/a3209ddf94136d36e5e5c624b10b2a347cc9d090

Now that I am defining NNRat.cast, I want a definitive answer to this naming issue. Plenty of lemmas in mathlib already use natCast/intCast/ratCast over nat_cast/int_cast/rat_cast, and this matches with the general expectation that underscore-separated name parts correspond to a single declaration.

@@ -43,7 +43,7 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   have hnat₁ : p ∣ n ^ 2 + 1 := by
     refine' Int.natCast_dvd_natCast.mp _
     simp only [n, Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, Int.natCast_dvd_natCast.mp]
-    refine' (ZMod.int_cast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
+    refine' (ZMod.intCast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
     simp only [m, Int.cast_pow, Int.cast_add, Int.cast_one, ZMod.coe_valMinAbs]
     rw [pow_two, ← hy]; exact add_left_neg 1
   have hnat₂ : n ≤ p / 2 := ZMod.natAbs_valMinAbs_le y

Reduce the diff of #11499

Renames

All in the Int namespace:

• ofNat_eq_cast → ofNat_eq_natCast
• cast_eq_cast_iff_Nat → natCast_inj
• natCast_eq_ofNat → ofNat_eq_natCast
• coe_nat_sub → natCast_sub
• coe_nat_nonneg → natCast_nonneg
• sign_coe_add_one → sign_natCast_add_one
• nat_succ_eq_int_succ → natCast_succ
• succ_neg_nat_succ → succ_neg_natCast_succ
• coe_pred_of_pos → natCast_pred_of_pos
• coe_nat_div → natCast_div
• coe_nat_ediv → natCast_ediv
• sign_coe_nat_of_nonzero → sign_natCast_of_ne_zero
• toNat_coe_nat → toNat_natCast
• toNat_coe_nat_add_one → toNat_natCast_add_one
• coe_nat_dvd → natCast_dvd_natCast
• coe_nat_dvd_left → natCast_dvd
• coe_nat_dvd_right → dvd_natCast
• le_coe_nat_sub → le_natCast_sub
• succ_coe_nat_pos → succ_natCast_pos
• coe_nat_modEq_iff → natCast_modEq_iff
• coe_natAbs → natCast_natAbs
• coe_nat_eq_zero → natCast_eq_zero
• coe_nat_ne_zero → natCast_ne_zero
• coe_nat_ne_zero_iff_pos → natCast_ne_zero_iff_pos
• abs_coe_nat → abs_natCast
• coe_nat_nonpos_iff → natCast_nonpos_iff

Also rename Nat.coe_nat_dvd to Nat.cast_dvd_cast

@@ -41,8 +41,8 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   let m := ZMod.valMinAbs y
   let n := Int.natAbs m
   have hnat₁ : p ∣ n ^ 2 + 1 := by
-    refine' Int.coe_nat_dvd.mp _
-    simp only [n, Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, Int.coe_nat_dvd.mp]
+    refine' Int.natCast_dvd_natCast.mp _
+    simp only [n, Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, Int.natCast_dvd_natCast.mp]
     refine' (ZMod.int_cast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
     simp only [m, Int.cast_pow, Int.cast_add, Int.cast_one, ZMod.coe_valMinAbs]
     rw [pow_two, ← hy]; exact add_left_neg 1

Move basic Nat lemmas from Data.Nat.Order.Basic and Data.Nat.Pow to Data.Nat.Defs. Most proofs need adapting, but that's easily solved by replacing the general mathlib lemmas by the new Std Nat-specific lemmas and using omega.

Other changes

• Move the last few lemmas left in Data.Nat.Pow to Algebra.GroupPower.Order
• Move the deprecated aliases from Data.Nat.Pow to Algebra.GroupPower.Order
• Move the bit/bit0/bit1 lemmas from Data.Nat.Order.Basic to Data.Nat.Bits
• Fix some fallout from not importing Data.Nat.Order.Basic anymore
• Add a few Nat-specific lemmas to help fix the fallout (look for nolint simpNF)
• Turn Nat.mul_self_le_mul_self_iff and Nat.mul_self_lt_mul_self_iff around (they were misnamed)
• Make more arguments to Nat.one_lt_pow implicit

@@ -82,6 +82,6 @@ theorem imo2008_q3 : ∀ N : ℕ, ∃ n : ℕ, n ≥ N ∧
   obtain ⟨n, hnat, hreal⟩ := p_lemma p hpp hpmod4 (by linarith [hineq₁, Nat.zero_le (N ^ 2)])
   have hineq₂ : n ^ 2 + 1 ≥ p := Nat.le_of_dvd (n ^ 2).succ_pos hnat
   have hineq₃ : n * n ≥ N * N := by linarith [hineq₁, hineq₂]
-  have hn_ge_N : n ≥ N := Nat.mul_self_le_mul_self_iff.mpr hineq₃
+  have hn_ge_N : n ≥ N := Nat.mul_self_le_mul_self_iff.1 hineq₃
   exact ⟨n, hn_ge_N, p, hpp, hnat, hreal⟩
 #align imo2008_q3 imo2008_q3

Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

@@ -42,9 +42,9 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   let n := Int.natAbs m
   have hnat₁ : p ∣ n ^ 2 + 1 := by
     refine' Int.coe_nat_dvd.mp _
-    simp only [Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, Int.coe_nat_dvd.mp]
+    simp only [n, Int.natAbs_sq, Int.coe_nat_pow, Int.ofNat_succ, Int.coe_nat_dvd.mp]
     refine' (ZMod.int_cast_zmod_eq_zero_iff_dvd (m ^ 2 + 1) p).mp _
-    simp only [Int.cast_pow, Int.cast_add, Int.cast_one, ZMod.coe_valMinAbs]
+    simp only [m, Int.cast_pow, Int.cast_add, Int.cast_one, ZMod.coe_valMinAbs]
     rw [pow_two, ← hy]; exact add_left_neg 1
   have hnat₂ : n ≤ p / 2 := ZMod.natAbs_valMinAbs_le y
   have hnat₃ : p ≥ 2 * n := by linarith [Nat.div_mul_le_self p 2]

Algebra.GroupPower.Lemmas used to be a big bag of lemmas that made it there on the criterion that they needed "more imports". This was completely untrue, as all lemmas could be moved to earlier files in PRs:

• #9440
• #9442
• #9443
• #9455
• #9456
• #9457
• #9459
• #9461
• #9463
• #9466
• #9501
• #9502
• #9503
• #9505
• #9551
• #9553
• #9720
• #9739
• #9740
• #9805
• #9806
• and this one

There are several reasons for this:

• Necessary lemmas have been moved to earlier files since lemmas were dumped in Algebra.GroupPower.Lemmas
• In the Lean 3 → Lean 4 transition, Std acquired basic Int and Nat lemmas which let us shortcircuit the part of the algebraic order hierarchy on which the corresponding general lemmas rest
• Some proofs were overpowered
• Some earlier files were tangled and I have untangled them

This PR finishes the job by moving the last few lemmas out of Algebra.GroupPower.Lemmas, which is therefore deleted.

@@ -3,7 +3,6 @@ Copyright (c) 2021 Manuel Candales. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
 -/
-import Mathlib.Algebra.GroupPower.Lemmas
 import Mathlib.Data.Real.Basic
 import Mathlib.Data.Real.Sqrt
 import Mathlib.Data.Nat.Prime

These lemmas can be proved earlier.

Part of #9411

Co-authored-by: Parcly Taxel <reddeloostw@gmail.com>

@@ -3,6 +3,7 @@ Copyright (c) 2021 Manuel Candales. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
 -/
+import Mathlib.Algebra.GroupPower.Lemmas
 import Mathlib.Data.Real.Basic
 import Mathlib.Data.Real.Sqrt
 import Mathlib.Data.Nat.Prime

The names for lemmas about monotonicity of (a ^ ·) and (· ^ n) were a mess. This PR tidies up everything related by following the naming convention for (a * ·) and (· * b). Namely, (a ^ ·) is pow_right and (· ^ n) is pow_left in lemma names. All lemma renames follow the corresponding multiplication lemma names closely.

Renames

Algebra.GroupPower.Order

• pow_mono → pow_right_mono
• pow_le_pow → pow_le_pow_right
• pow_le_pow_of_le_left → pow_le_pow_left
• pow_lt_pow_of_lt_left → pow_lt_pow_left
• strictMonoOn_pow → pow_left_strictMonoOn
• pow_strictMono_right → pow_right_strictMono
• pow_lt_pow → pow_lt_pow_right
• pow_lt_pow_iff → pow_lt_pow_iff_right
• pow_le_pow_iff → pow_le_pow_iff_right
• self_lt_pow → lt_self_pow
• strictAnti_pow → pow_right_strictAnti
• pow_lt_pow_iff_of_lt_one → pow_lt_pow_iff_right_of_lt_one
• pow_lt_pow_of_lt_one → pow_lt_pow_right_of_lt_one
• lt_of_pow_lt_pow → lt_of_pow_lt_pow_left
• le_of_pow_le_pow → le_of_pow_le_pow_left
• pow_lt_pow₀ → pow_lt_pow_right₀

Algebra.GroupPower.CovariantClass

• pow_le_pow_of_le_left' → pow_le_pow_left'
• nsmul_le_nsmul_of_le_right → nsmul_le_nsmul_right
• pow_lt_pow' → pow_lt_pow_right'
• nsmul_lt_nsmul → nsmul_lt_nsmul_left
• pow_strictMono_left → pow_right_strictMono'
• nsmul_strictMono_right → nsmul_left_strictMono
• StrictMono.pow_right' → StrictMono.pow_const
• StrictMono.nsmul_left → StrictMono.const_nsmul
• pow_strictMono_right' → pow_left_strictMono
• nsmul_strictMono_left → nsmul_right_strictMono
• Monotone.pow_right → Monotone.pow_const
• Monotone.nsmul_left → Monotone.const_nsmul
• lt_of_pow_lt_pow' → lt_of_pow_lt_pow_left'
• lt_of_nsmul_lt_nsmul → lt_of_nsmul_lt_nsmul_right
• pow_le_pow' → pow_le_pow_right'
• nsmul_le_nsmul → nsmul_le_nsmul_left
• pow_le_pow_of_le_one' → pow_le_pow_right_of_le_one'
• nsmul_le_nsmul_of_nonpos → nsmul_le_nsmul_left_of_nonpos
• le_of_pow_le_pow' → le_of_pow_le_pow_left'
• le_of_nsmul_le_nsmul' → le_of_nsmul_le_nsmul_right'
• pow_le_pow_iff' → pow_le_pow_iff_right'
• nsmul_le_nsmul_iff → nsmul_le_nsmul_iff_left
• pow_lt_pow_iff' → pow_lt_pow_iff_right'
• nsmul_lt_nsmul_iff → nsmul_lt_nsmul_iff_left

Data.Nat.Pow

• Nat.pow_lt_pow_of_lt_left → Nat.pow_lt_pow_left
• Nat.pow_le_iff_le_left → Nat.pow_le_pow_iff_left
• Nat.pow_lt_iff_lt_left → Nat.pow_lt_pow_iff_left

Lemmas added

• pow_le_pow_iff_left
• pow_lt_pow_iff_left
• pow_right_injective
• pow_right_inj
• Nat.pow_le_pow_left to have the correct name since Nat.pow_le_pow_of_le_left is in Std.
• Nat.pow_le_pow_right to have the correct name since Nat.pow_le_pow_of_le_right is in Std.

Lemmas removed

• self_le_pow was a duplicate of le_self_pow.
• Nat.pow_lt_pow_of_lt_right is defeq to pow_lt_pow_right.
• Nat.pow_right_strictMono is defeq to pow_right_strictMono.
• Nat.pow_le_iff_le_right is defeq to pow_le_pow_iff_right.
• Nat.pow_lt_iff_lt_right is defeq to pow_lt_pow_iff_right.

Other changes

• A bunch of proofs have been golfed.
• Some lemma assumptions have been turned from 0 < n or 1 ≤ n to n ≠ 0.
• A few Nat lemmas have been protected.
• One docstring has been fixed.

@@ -62,10 +62,10 @@ theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4])
   have hreal₂ : (p : ℝ) > 20 := by assumption_mod_cast
   have hreal₃ : (k : ℝ) ^ 2 + 4 ≥ p := by assumption_mod_cast
   have hreal₅ : (k : ℝ) > 4 := by
-    refine' lt_of_pow_lt_pow 2 k.cast_nonneg _
+    refine' lt_of_pow_lt_pow_left 2 k.cast_nonneg _
     linarith only [hreal₂, hreal₃]
   have hreal₆ : (k : ℝ) > sqrt (2 * n) := by
-    refine' lt_of_pow_lt_pow 2 k.cast_nonneg _
+    refine' lt_of_pow_lt_pow_left 2 k.cast_nonneg _
     rw [sq_sqrt (mul_nonneg zero_le_two n.cast_nonneg)]
     linarith only [hreal₁, hreal₃, hreal₅]
   exact ⟨n, hnat₁, by linarith only [hreal₆, hreal₁]⟩

PR contents

This is the supremum of

• #8284
• #8056
• #8023
• #8332
• #8226 (already approved)
• #7834 (already approved)

along with some minor fixes from failures on nightly-testing as Mathlib master is merged into it.

Note that some PRs for changes that are already compatible with the current toolchain and will be necessary have already been split out: #8380.

I am hopeful that in future we will be able to progressively merge adaptation PRs into a bump/v4.X.0 branch, so we never end up with a "big merge" like this. However one of these adaptation PRs (#8056) predates my new scheme for combined CI, and it wasn't possible to keep that PR viable in the meantime.

Lean PRs involved in this bump

In particular this includes adjustments for the Lean PRs

• leanprover/lean4#2778
• leanprover/lean4#2790
• leanprover/lean4#2783
• leanprover/lean4#2825
• leanprover/lean4#2722

leanprover/lean4#2778

We can get rid of all the

local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue [lean4#2220](https://github.com/leanprover/lean4/pull/2220)

macros across Mathlib (and in any projects that want to write natural number powers of reals).

leanprover/lean4#2722

Changes the default behaviour of simp to (config := {decide := false}). This makes simp (and consequentially norm_num) less powerful, but also more consistent, and less likely to blow up in long failures. This requires a variety of changes: changing some previously by simp or norm_num to decide or rfl, or adding (config := {decide := true}).

leanprover/lean4#2783

This changed the behaviour of simp so that simp [f] will only unfold "fully applied" occurrences of f. The old behaviour can be recovered with simp (config := { unfoldPartialApp := true }). We may in future add a syntax for this, e.g. simp [!f]; please provide feedback! In the meantime, we have made the following changes:

• switching to using explicit lemmas that have the intended level of application
• (config := { unfoldPartialApp := true }) in some places, to recover the old behaviour
• Using @[eqns] to manually adjust the equation lemmas for a particular definition, recovering the old behaviour just for that definition. See #8371, where we do this for Function.comp and Function.flip.

This change in Lean may require further changes down the line (e.g. adding the !f syntax, and/or upstreaming the special treatment for Function.comp and Function.flip, and/or removing this special treatment). Please keep an open and skeptical mind about these changes!

Co-authored-by: leanprover-community-mathlib4-bot <leanprover-community-mathlib4-bot@users.noreply.github.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Mauricio Collares <mauricio@collares.org>

@@ -31,8 +31,6 @@ Then `p = 2n + k ≥ 2n + √(p - 4) = 2n + √(2n + k - 4) > √(2n)` and we ar
 
 open Real
 
-local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue lean4#2220
-
 namespace Imo2008Q3
 
 theorem p_lemma (p : ℕ) (hpp : Nat.Prime p) (hp_mod_4_eq_1 : p ≡ 1 [MOD 4]) (hp_gt_20 : p > 20) :

@@ -31,7 +31,7 @@ Then `p = 2n + k ≥ 2n + √(p - 4) = 2n + √(2n + k - 4) > √(2n)` and we ar
 
 open Real
 
-local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue #2220
+local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue lean4#2220
 
 namespace Imo2008Q3
 

• depends on: #5966

Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

@@ -2,11 +2,6 @@
 Copyright (c) 2021 Manuel Candales. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Manuel Candales
-
-! This file was ported from Lean 3 source module imo.imo2008_q3
-! leanprover-community/mathlib commit 308826471968962c6b59c7ff82a22757386603e3
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Data.Real.Basic
 import Mathlib.Data.Real.Sqrt
@@ -15,6 +10,8 @@ import Mathlib.NumberTheory.PrimesCongruentOne
 import Mathlib.NumberTheory.LegendreSymbol.QuadraticReciprocity
 import Mathlib.Tactic.LinearCombination
 
+#align_import imo.imo2008_q3 from "leanprover-community/mathlib"@"308826471968962c6b59c7ff82a22757386603e3"
+
 /-!
 # IMO 2008 Q3
 Prove that there exist infinitely many positive integers `n` such that `n^2 + 1` has a prime