url
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147 values
commit
stringclasses
147 values
file_path
stringlengths
7
101
full_name
stringlengths
1
94
start
stringlengths
6
10
end
stringlengths
6
11
tactic
stringlengths
1
11.2k
state_before
stringlengths
3
2.09M
state_after
stringlengths
6
2.09M
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
case hx n : ℝ hn : 0 < n ⊒ 0 < 2 * n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 ≀ 2 * n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 ≀ 20 * (2 * n) ^ (2 / 3)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
norm_num
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 3
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
norm_num
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 ≀ 20
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 ≀ (2 * n) ^ (2 / 3)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
norm_num
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 3 = 1 + 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 2 * n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
norm_num
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 20
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
apply sq_pos_of_pos
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < (2 * n) ^ 2
case ha n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 2 * n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
linarith
case ha n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 2 * n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
lt4kIff
[143, 1]
[160, 11]
norm_num
n : ℝ hn : 0 < n h_nonneg : 0 < (2 * n) ^ (2 / 3) ⊒ 0 < 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
intro hn
n : β„• ⊒ 0 < n β†’ βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p
n : β„• hn : 0 < n ⊒ βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
cases lt_or_le n 4000 with | inl hn' => exact landauTrick (by linarith) (by linarith) | inr hn' => by_contra h simp at h replace h : ∏ p in primes (Finset.Ioc n (2*n)), p = 1 . apply Finset.prod_eq_one intro i hi specialize h i simp [primes] at * specialize h hi.left.left hi.left.right hi.right contradiction have h' := fourPowLeMulProdPrimes (by linarith : 2 < n) simp [h] at h'; clear h replace h' := rpowDivThreeLe (by linarith : 0 < n) h' have : (81 / 2 : ℝ) < ↑n . rw [div_lt_iff (by norm_num)]; norm_cast; linarith replace h' := fourPowLtOf this h'; clear this rw [lt4kIff (by norm_cast)] at h' norm_cast at h' linarith
n : β„• hn : 0 < n ⊒ βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
exact landauTrick (by linarith) (by linarith)
case inl n : β„• hn : 0 < n hn' : n < 4000 ⊒ βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
n : β„• hn : 0 < n hn' : n < 4000 ⊒ 0 < n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
n : β„• hn : 0 < n hn' : n < 4000 ⊒ n ≀ 4000
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
by_contra h
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n ⊒ βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : Β¬βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
simp at h
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : Β¬βˆƒ p, p ∈ Set.Ioc n (2 * n) ∧ Nat.Prime p ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
replace h : ∏ p in primes (Finset.Ioc n (2*n)), p = 1
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ False
case h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
. apply Finset.prod_eq_one intro i hi specialize h i simp [primes] at * specialize h hi.left.left hi.left.right hi.right contradiction
case h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
have h' := fourPowLeMulProdPrimes (by linarith : 2 < n)
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) * ∏ p in primes (Finset.Ioc n (2 * n)), p ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
simp [h] at h'
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) * ∏ p in primes (Finset.Ioc n (2 * n)), p ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
clear h
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
replace h' := rpowDivThreeLe (by linarith : 0 < n) h'
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
have : (81 / 2 : ℝ) < ↑n
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ False
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 / 2 < ↑n case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) this : 81 / 2 < ↑n ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
. rw [div_lt_iff (by norm_num)]; norm_cast; linarith
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 / 2 < ↑n case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) this : 81 / 2 < ↑n ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) this : 81 / 2 < ↑n ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
replace h' := fourPowLtOf this h'
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) this : 81 / 2 < ↑n ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n this : 81 / 2 < ↑n h' : 4 ^ ↑n < 2 ^ (20 * (2 * ↑n) ^ (2 / 3)) ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
clear this
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n this : 81 / 2 < ↑n h' : 4 ^ ↑n < 2 ^ (20 * (2 * ↑n) ^ (2 / 3)) ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ ↑n < 2 ^ (20 * (2 * ↑n) ^ (2 / 3)) ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
rw [lt4kIff (by norm_cast)] at h'
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ ↑n < 2 ^ (20 * (2 * ↑n) ^ (2 / 3)) ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : ↑n < 4000 ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
norm_cast at h'
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : ↑n < 4000 ⊒ False
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : n < 4000 ⊒ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
case inr n : β„• hn : 0 < n hn' : 4000 ≀ n h' : n < 4000 ⊒ False
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
apply Finset.prod_eq_one
case h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ ∏ p in primes (Finset.Ioc n (2 * n)), p = 1
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ βˆ€ (x : β„•), x ∈ primes (Finset.Ioc n (2 * n)) β†’ x = 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
intro i hi
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x ⊒ βˆ€ (x : β„•), x ∈ primes (Finset.Ioc n (2 * n)) β†’ x = 1
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x i : β„• hi : i ∈ primes (Finset.Ioc n (2 * n)) ⊒ i = 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
specialize h i
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n h : βˆ€ (x : β„•), n < x β†’ x ≀ 2 * n β†’ Β¬Nat.Prime x i : β„• hi : i ∈ primes (Finset.Ioc n (2 * n)) ⊒ i = 1
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• hi : i ∈ primes (Finset.Ioc n (2 * n)) h : n < i β†’ i ≀ 2 * n β†’ Β¬Nat.Prime i ⊒ i = 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
simp [primes] at *
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• hi : i ∈ primes (Finset.Ioc n (2 * n)) h : n < i β†’ i ≀ 2 * n β†’ Β¬Nat.Prime i ⊒ i = 1
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• h : n < i β†’ i ≀ 2 * n β†’ Β¬Nat.Prime i hi : (n < i ∧ i ≀ 2 * n) ∧ Nat.Prime i ⊒ i = 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
specialize h hi.left.left hi.left.right hi.right
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• h : n < i β†’ i ≀ 2 * n β†’ Β¬Nat.Prime i hi : (n < i ∧ i ≀ 2 * n) ∧ Nat.Prime i ⊒ i = 1
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• hi : (n < i ∧ i ≀ 2 * n) ∧ Nat.Prime i h : False ⊒ i = 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
contradiction
case h.h n : β„• hn : 0 < n hn' : 4000 ≀ n i : β„• hi : (n < i ∧ i ≀ 2 * n) ∧ Nat.Prime i h : False ⊒ i = 1
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
n : β„• hn : 0 < n hn' : 4000 ≀ n h : ∏ p in primes (Finset.Ioc n (2 * n)), p = 1 ⊒ 2 < n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ n ≀ (2 * n) ^ (1 + Nat.sqrt (2 * n)) * 4 ^ Nat.pred (2 * n / 3) ⊒ 0 < n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
rw [div_lt_iff (by norm_num)]
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 / 2 < ↑n
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 < ↑n * 2
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
norm_cast
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 < ↑n * 2
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 < n * 2
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
linarith
case this n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 81 < n * 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
norm_num
n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ (↑n / 3) ≀ (2 * ↑n) ^ (1 + Real.sqrt (2 * ↑n)) ⊒ 0 < 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/Bertrand.lean
bertrand
[162, 1]
[184, 13]
norm_cast
n : β„• hn : 0 < n hn' : 4000 ≀ n h' : 4 ^ ↑n < 2 ^ (20 * (2 * ↑n) ^ (2 / 3)) ⊒ 0 < ↑n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
chooseHalfLePowFour
[21, 1]
[28, 46]
rw [Nat.Ico_succ_singleton]
m : β„• ⊒ βˆ‘ k in {m}, Nat.choose (2 * m + 1) k = βˆ‘ k in Finset.Ico m (m + 1), Nat.choose (2 * m + 1) k
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
chooseHalfLePowFour
[21, 1]
[28, 46]
rw [Finset.range_eq_Ico]
m : β„• ⊒ βˆ‘ k in Finset.Ico 0 (m + 1), Nat.choose (2 * m + 1) k = βˆ‘ k in Finset.range (m + 1), Nat.choose (2 * m + 1) k
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
rw [primes]
m : β„• ⊒ ∏ p in primes (Finset.Ioc (m + 1) (2 * m + 1)), p ≀ Nat.choose (2 * m + 1) m
m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ≀ Nat.choose (2 * m + 1) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
apply Nat.le_of_dvd
m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ≀ Nat.choose (2 * m + 1) m
case h m : β„• ⊒ 0 < Nat.choose (2 * m + 1) m case a m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ∣ Nat.choose (2 * m + 1) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
. apply Nat.choose_pos; linarith
case h m : β„• ⊒ 0 < Nat.choose (2 * m + 1) m case a m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ∣ Nat.choose (2 * m + 1) m
case a m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ∣ Nat.choose (2 * m + 1) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
apply Finset.prod_primes_dvd <;> simp [← Nat.prime_iff]
case a m : β„• ⊒ ∏ p in Finset.filter Nat.Prime (Finset.Ioc (m + 1) (2 * m + 1)), p ∣ Nat.choose (2 * m + 1) m
case a.div m : β„• ⊒ βˆ€ (a : β„•), m + 1 < a β†’ a ≀ 2 * m + 1 β†’ Nat.Prime a β†’ a ∣ Nat.choose (2 * m + 1) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
intro p ha hb hp
case a.div m : β„• ⊒ βˆ€ (a : β„•), m + 1 < a β†’ a ≀ 2 * m + 1 β†’ Nat.Prime a β†’ a ∣ Nat.choose (2 * m + 1) m
case a.div m p : β„• ha : m + 1 < p hb : p ≀ 2 * m + 1 hp : Nat.Prime p ⊒ p ∣ Nat.choose (2 * m + 1) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
rw [two_mul, add_assoc]
case a.div m p : β„• ha : m + 1 < p hb : p ≀ 2 * m + 1 hp : Nat.Prime p ⊒ p ∣ Nat.choose (2 * m + 1) m
case a.div m p : β„• ha : m + 1 < p hb : p ≀ 2 * m + 1 hp : Nat.Prime p ⊒ p ∣ Nat.choose (m + (m + 1)) m
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
apply Nat.Prime.dvd_choose_add hp <;> linarith
case a.div m p : β„• ha : m + 1 < p hb : p ≀ 2 * m + 1 hp : Nat.Prime p ⊒ p ∣ Nat.choose (m + (m + 1)) m
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
apply Nat.choose_pos
case h m : β„• ⊒ 0 < Nat.choose (2 * m + 1) m
case h.a m : β„• ⊒ m ≀ 2 * m + 1
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesIocLeChoose
[30, 1]
[39, 49]
linarith
case h.a m : β„• ⊒ m ≀ 2 * m + 1
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
primesSuccEqPrimesSelf
[41, 1]
[46, 13]
simp [primes]
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ primes (Finset.range (Nat.succ (Nat.succ n))) = primes (Finset.range (Nat.succ n))
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Finset.filter Nat.Prime (Finset.range (Nat.succ (Nat.succ n))) = Finset.filter Nat.Prime (Finset.range (Nat.succ n))
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
primesSuccEqPrimesSelf
[41, 1]
[46, 13]
rw [Finset.range_succ]
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Finset.filter Nat.Prime (Finset.range (Nat.succ (Nat.succ n))) = Finset.filter Nat.Prime (Finset.range (Nat.succ n))
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Finset.filter Nat.Prime (insert (n + 1) (Finset.range (n + 1))) = Finset.filter Nat.Prime (Finset.range (Nat.succ n))
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
primesSuccEqPrimesSelf
[41, 1]
[46, 13]
simp [Finset.filter_insert]
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Finset.filter Nat.Prime (insert (n + 1) (Finset.range (n + 1))) = Finset.filter Nat.Prime (Finset.range (Nat.succ n))
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Nat.Prime (n + 1) β†’ False
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
primesSuccEqPrimesSelf
[41, 1]
[46, 13]
assumption
n : β„• hn : Β¬Nat.Prime (Nat.succ n) ⊒ Nat.Prime (n + 1) β†’ False
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
intro n
p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) ⊒ βˆ€ (n : β„•), p n
p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) n : β„• ⊒ p n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
induction n using Nat.caseStrongInductionOn with | zero => exact zero | ind k h_ind => cases dec_em (Nat.Prime k.succ) with | inr hk_prime => apply not_prime _ hk_prime exact h_ind | inl hk_prime => cases Nat.Prime.eq_two_or_odd' hk_prime with | inl hk_two => rw [hk_two]; exact two | inr hk_two => cases hk_two with | intro m hm => simp [Nat.add_one] at hm simp [hm] at * apply odd_prime _ hk_prime h_ind
p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) n : β„• ⊒ p n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
exact zero
case zero p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) ⊒ p 0
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
cases dec_em (Nat.Prime k.succ) with | inr hk_prime => apply not_prime _ hk_prime exact h_ind | inl hk_prime => cases Nat.Prime.eq_two_or_odd' hk_prime with | inl hk_two => rw [hk_two]; exact two | inr hk_two => cases hk_two with | intro m hm => simp [Nat.add_one] at hm simp [hm] at * apply odd_prime _ hk_prime h_ind
case ind p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m ⊒ p (Nat.succ k)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
apply not_prime _ hk_prime
case ind.inr p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Β¬Nat.Prime (Nat.succ k) ⊒ p (Nat.succ k)
case ind.inr p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Β¬Nat.Prime (Nat.succ k) ⊒ βˆ€ (x : β„•), x ≀ k β†’ p x
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
exact h_ind
case ind.inr p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Β¬Nat.Prime (Nat.succ k) ⊒ βˆ€ (x : β„•), x ≀ k β†’ p x
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
cases Nat.Prime.eq_two_or_odd' hk_prime with | inl hk_two => rw [hk_two]; exact two | inr hk_two => cases hk_two with | intro m hm => simp [Nat.add_one] at hm simp [hm] at * apply odd_prime _ hk_prime h_ind
case ind.inl p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) ⊒ p (Nat.succ k)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
rw [hk_two]
case ind.inl.inl p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) hk_two : Nat.succ k = 2 ⊒ p (Nat.succ k)
case ind.inl.inl p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) hk_two : Nat.succ k = 2 ⊒ p 2
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
exact two
case ind.inl.inl p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) hk_two : Nat.succ k = 2 ⊒ p 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
cases hk_two with | intro m hm => simp [Nat.add_one] at hm simp [hm] at * apply odd_prime _ hk_prime h_ind
case ind.inl.inr p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) hk_two : Odd (Nat.succ k) ⊒ p (Nat.succ k)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
simp [Nat.add_one] at hm
case ind.inl.inr.intro p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) m : β„• hm : Nat.succ k = 2 * m + 1 ⊒ p (Nat.succ k)
case ind.inl.inr.intro p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) m : β„• hm : k = 2 * m ⊒ p (Nat.succ k)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
simp [hm] at *
case ind.inl.inr.intro p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k : β„• h_ind : βˆ€ (m : β„•), m ≀ k β†’ p m hk_prime : Nat.Prime (Nat.succ k) m : β„• hm : k = 2 * m ⊒ p (Nat.succ k)
case ind.inl.inr.intro p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k m : β„• h_ind : βˆ€ (m_1 : β„•), m_1 ≀ 2 * m β†’ p m_1 hk_prime : Nat.Prime (Nat.succ (2 * m)) hm : True ⊒ p (Nat.succ (2 * m))
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
caseStrongRecOnOddPrimes
[48, 1]
[70, 43]
apply odd_prime _ hk_prime h_ind
case ind.inl.inr.intro p : β„• β†’ Prop zero : p 0 two : p 2 not_prime : βˆ€ (n : β„•), Β¬Nat.Prime (Nat.succ n) β†’ (βˆ€ (x : β„•), x ≀ n β†’ p x) β†’ p (Nat.succ n) odd_prime : βˆ€ (n : β„•), Nat.Prime (Nat.succ (2 * n)) β†’ (βˆ€ (x : β„•), x ≀ 2 * n β†’ p x) β†’ p (Nat.succ (2 * n)) k m : β„• h_ind : βˆ€ (m_1 : β„•), m_1 ≀ 2 * m β†’ p m_1 hk_prime : Nat.Prime (Nat.succ (2 * m)) hm : True ⊒ p (Nat.succ (2 * m))
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
induction n using caseStrongRecOnOddPrimes with | zero => simp | two => simp | not_prime n hp hi => specialize hi n simp at hi cases n with | zero => simp | succ n => simp only [Nat.pred_succ] at * simp [prodPrimes] rw [primesSuccEqPrimesSelf hp, Nat.add_one] rw [← prodPrimes, Nat.add_one] apply le_trans hi simp [pow_succ] | odd_prime n hp hi => simp conv => rhs; rw [two_mul, pow_add] specialize hi n.succ _ . cases n with | zero => contradiction | succ n => linarith simp at hi rw [prodPrimesSplit (by linarith : n.succ ≀ (2*n).succ)] apply Nat.mul_le_mul hi apply le_trans _ chooseHalfLePowFour exact prodPrimesIocLeChoose
n : β„• ⊒ prodPrimes n ≀ 4 ^ Nat.pred n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp
case zero ⊒ prodPrimes 0 ≀ 4 ^ Nat.pred 0
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp
case two ⊒ prodPrimes 2 ≀ 4 ^ Nat.pred 2
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
specialize hi n
case not_prime n : β„• hp : Β¬Nat.Prime (Nat.succ n) hi : βˆ€ (x : β„•), x ≀ n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n)
case not_prime n : β„• hp : Β¬Nat.Prime (Nat.succ n) hi : n ≀ n β†’ prodPrimes n ≀ 4 ^ Nat.pred n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp at hi
case not_prime n : β„• hp : Β¬Nat.Prime (Nat.succ n) hi : n ≀ n β†’ prodPrimes n ≀ 4 ^ Nat.pred n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n)
case not_prime n : β„• hp : Β¬Nat.Prime (Nat.succ n) hi : prodPrimes n ≀ 4 ^ Nat.pred n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
cases n with | zero => simp | succ n => simp only [Nat.pred_succ] at * simp [prodPrimes] rw [primesSuccEqPrimesSelf hp, Nat.add_one] rw [← prodPrimes, Nat.add_one] apply le_trans hi simp [pow_succ]
case not_prime n : β„• hp : Β¬Nat.Prime (Nat.succ n) hi : prodPrimes n ≀ 4 ^ Nat.pred n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp
case not_prime.zero hp : Β¬Nat.Prime (Nat.succ Nat.zero) hi : prodPrimes Nat.zero ≀ 4 ^ Nat.pred Nat.zero ⊒ prodPrimes (Nat.succ Nat.zero) ≀ 4 ^ Nat.pred (Nat.succ Nat.zero)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp only [Nat.pred_succ] at *
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n) ⊒ prodPrimes (Nat.succ (Nat.succ n)) ≀ 4 ^ Nat.pred (Nat.succ (Nat.succ n))
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ (Nat.succ n)) ≀ 4 ^ (n + 1)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp [prodPrimes]
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ (Nat.succ n)) ≀ 4 ^ (n + 1)
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.range (Nat.succ (Nat.succ (Nat.succ n)))), p ≀ 4 ^ (n + 1)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
rw [primesSuccEqPrimesSelf hp, Nat.add_one]
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.range (Nat.succ (Nat.succ (Nat.succ n)))), p ≀ 4 ^ (n + 1)
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.range (Nat.succ (Nat.succ n))), p ≀ 4 ^ Nat.succ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
rw [← prodPrimes, Nat.add_one]
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.range (Nat.succ (Nat.succ n))), p ≀ 4 ^ Nat.succ n
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.succ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
apply le_trans hi
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ n) ≀ 4 ^ Nat.succ n
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ 4 ^ n ≀ 4 ^ Nat.succ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp [pow_succ]
case not_prime.succ n : β„• hp : Β¬Nat.Prime (Nat.succ (Nat.succ n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ 4 ^ n ≀ 4 ^ Nat.succ n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ Nat.pred (Nat.succ (2 * n))
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ (2 * n)
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
conv => rhs; rw [two_mul, pow_add]
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ (2 * n)
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
specialize hi n.succ _
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ Nat.succ n ≀ 2 * n case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n) ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
. cases n with | zero => contradiction | succ n => linarith
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ Nat.succ n ≀ 2 * n case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n) ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n) ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
simp at hi
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ Nat.pred (Nat.succ n) ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
rw [prodPrimesSplit (by linarith : n.succ ≀ (2*n).succ)]
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ (2 * n)) ≀ 4 ^ n * 4 ^ n
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ n) * ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ 4 ^ n * 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
apply Nat.mul_le_mul hi
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ prodPrimes (Nat.succ n) * ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ 4 ^ n * 4 ^ n
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ 4 ^ n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
apply le_trans _ chooseHalfLePowFour
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ 4 ^ n
n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ Nat.choose (2 * n + 1) n
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
exact prodPrimesIocLeChoose
n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ ∏ p in primes (Finset.Ioc (Nat.succ n) (Nat.succ (2 * n))), p ≀ Nat.choose (2 * n + 1) n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
cases n with | zero => contradiction | succ n => linarith
case odd_prime n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : βˆ€ (x : β„•), x ≀ 2 * n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ Nat.succ n ≀ 2 * n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
contradiction
case odd_prime.zero hp : Nat.Prime (Nat.succ (2 * Nat.zero)) hi : βˆ€ (x : β„•), x ≀ 2 * Nat.zero β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ Nat.succ Nat.zero ≀ 2 * Nat.zero
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
linarith
case odd_prime.succ n : β„• hp : Nat.Prime (Nat.succ (2 * Nat.succ n)) hi : βˆ€ (x : β„•), x ≀ 2 * Nat.succ n β†’ prodPrimes x ≀ 4 ^ Nat.pred x ⊒ Nat.succ (Nat.succ n) ≀ 2 * Nat.succ n
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesLePowFour
[77, 1]
[104, 32]
linarith
n : β„• hp : Nat.Prime (Nat.succ (2 * n)) hi : prodPrimes (Nat.succ n) ≀ 4 ^ n ⊒ Nat.succ n ≀ Nat.succ (2 * n)
no goals
https://github.com/jvlmdr/from_the_book.git
9fb6080539a2f32bb24719600a9e7531abf2328d
FromTheBook/Ch02/Bertrand/ProdPrimes.lean
prodPrimesRealLePowFour
[106, 1]
[116, 15]
norm_cast
x : ℝ hx : 1 ≀ x ⊒ ↑(prodPrimes ⌊xβŒ‹β‚Š) ≀ ↑(4 ^ (⌊xβŒ‹β‚Š - 1))
x : ℝ hx : 1 ≀ x ⊒ prodPrimes ⌊xβŒ‹β‚Š ≀ 4 ^ (⌊xβŒ‹β‚Š - 1)