Theorem: Nat.lt_of_testBit
File: Mathlib/Data/Nat/Bitwise.lean

Proof steps:
state_before: n m i : ℕ
hn : n.testBit i = false
hm : m.testBit i = true
hnm : ∀ (j : ℕ), i < j → n.testBit j = m.testBit j
⊢ n < m
state_after: case z
m i : ℕ
hn : testBit 0 i = false
hm : m.testBit i = true
hnm : ∀ (j : ℕ), i < j → testBit 0 j = m.testBit j
⊢ 0 < m

case f
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
m i : ℕ
hn : (bit b n).testBit i = false
hm : m.testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j
⊢ bit b n < m
tactic: induction' n using Nat.binaryRec with b n hn' generalizing i m
state_before: case f
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
m i : ℕ
hn : (bit b n).testBit i = false
hm : m.testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j
⊢ bit b n < m
state_after: case f.z
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
i : ℕ
hn : (bit b n).testBit i = false
hm : testBit 0 i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = testBit 0 j
⊢ bit b n < 0

case f.f
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
b' : Bool
m : ℕ
hm' :
  ∀ (i : ℕ),
    (bit b n).testBit i = false →
      m.testBit i = true → (∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j) → bit b n < m
i : ℕ
hn : (bit b n).testBit i = false
hm : (bit b' m).testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = (bit b' m).testBit j
⊢ bit b n < bit b' m
tactic: induction' m using Nat.binaryRec with b' m hm' generalizing i
state_before: case f.f
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
b' : Bool
m : ℕ
hm' :
  ∀ (i : ℕ),
    (bit b n).testBit i = false →
      m.testBit i = true → (∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j) → bit b n < m
i : ℕ
hn : (bit b n).testBit i = false
hm : (bit b' m).testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = (bit b' m).testBit j
⊢ bit b n < bit b' m
state_after: case pos
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
b' : Bool
m : ℕ
hm' :
  ∀ (i : ℕ),
    (bit b n).testBit i = false →
      m.testBit i = true → (∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j) → bit b n < m
i : ℕ
hn : (bit b n).testBit i = false
hm : (bit b' m).testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = (bit b' m).testBit j
hi : i = 0
⊢ bit b n < bit b' m

case neg
b : Bool
n : ℕ
hn' :
  ∀ {m : ℕ} (i : ℕ), n.testBit i = false → m.testBit i = true → (∀ (j : ℕ), i < j → n.testBit j = m.testBit j) → n < m
b' : Bool
m : ℕ
hm' :
  ∀ (i : ℕ),
    (bit b n).testBit i = false →
      m.testBit i = true → (∀ (j : ℕ), i < j → (bit b n).testBit j = m.testBit j) → bit b n < m
i : ℕ
hn : (bit b n).testBit i = false
hm : (bit b' m).testBit i = true
hnm : ∀ (j : ℕ), i < j → (bit b n).testBit j = (bit b' m).testBit j
hi : ¬i = 0
⊢ bit b n < bit b' m
tactic: by_cases hi : i = 0