apply Or.inr ∘ Or.inr
case inr.inr.intro.intro.intro.intro.intro.intro.intro.intro
rupHints : Array Nat
n : Nat
f : DefaultFormula n
f_assignments_size : f.assignments.size = n
f' : DefaultFormula n
_f'_def : f' = (f.performRupCheck rupHints).fst
f'_assignments_size : f'.assignments.size = n
derivedLits : List (Literal (PosFin n))
derivedLits_arr : Array (Literal (PosFin n))
derivedLits_arr_def : derivedLits_arr = { data := derivedLits }
_derivedLits_arr_nodup : ∀ (i j : Fin derivedLits_arr.size), i ≠ j → derivedLits_arr[i] ≠ derivedLits_arr[j]
i : Fin n
j1 j2 : Fin derivedLits.length
j1_eq_i : (derivedLits.get j1).fst.val = ↑i
j2_eq_i : (derivedLits.get j2).fst.val = ↑i
j1_eq_true : (derivedLits.get j1).snd = true
j2_eq_false : (derivedLits.get j2).snd = false
h1 : f'.assignments[↑i] = both
h2 : f.assignments[↑i] = unassigned
h3 : ∀ (k : Fin derivedLits.length), k ≠ j1 → k ≠ j2 → (derivedLits.get k).fst.val ≠ ↑i
⊢ let_fun i_lt_assignments_size := ⋯;
  let_fun i_lt_f_assignments_size := ⋯;
  let assignments_i := f'.assignments[↑i];
  let fassignments_i := f.assignments[↑i];
  (assignments_i = fassignments_i ∧ ∀ (j : Fin derivedLits_arr.size), ↑j ≥ 0 → derivedLits_arr[j].fst.val ≠ ↑i) ∨
    (∃ j b i_gt_zero,
        ↑j ≥ 0 ∧
          derivedLits_arr[j] = (⟨↑i, ⋯⟩, b) ∧
            assignments_i = addAssignment b fassignments_i ∧
              ¬hasAssignment b fassignments_i = true ∧
                ∀ (k : Fin derivedLits_arr.size), ↑k ≥ 0 → k ≠ j → derivedLits_arr[k].fst.val ≠ ↑i) ∨
      ∃ j1 j2 i_gt_zero,
        ↑j1 ≥ 0 ∧
          ↑j2 ≥ 0 ∧
            derivedLits_arr[j1] = (⟨↑i, ⋯⟩, true) ∧
              derivedLits_arr[j2] = (⟨↑i, ⋯⟩, false) ∧
                assignments_i = both ∧
                  fassignments_i = unassigned ∧
                    ∀ (k : Fin derivedLits_arr.size), ↑k ≥ 0 → k ≠ j1 → k ≠ j2 → derivedLits_arr[k].fst.val ≠ ↑i
case inr.inr.intro.intro.intro.intro.intro.intro.intro.intro
rupHints : Array Nat
n : Nat
f : DefaultFormula n
f_assignments_size : f.assignments.size = n
f' : DefaultFormula n
_f'_def : f' = (f.performRupCheck rupHints).fst
f'_assignments_size : f'.assignments.size = n
derivedLits : List (Literal (PosFin n))
derivedLits_arr : Array (Literal (PosFin n))
derivedLits_arr_def : derivedLits_arr = { data := derivedLits }
_derivedLits_arr_nodup : ∀ (i j : Fin derivedLits_arr.size), i ≠ j → derivedLits_arr[i] ≠ derivedLits_arr[j]
i : Fin n
j1 j2 : Fin derivedLits.length
j1_eq_i : (derivedLits.get j1).fst.val = ↑i
j2_eq_i : (derivedLits.get j2).fst.val = ↑i
j1_eq_true : (derivedLits.get j1).snd = true
j2_eq_false : (derivedLits.get j2).snd = false
h1 : f'.assignments[↑i] = both
h2 : f.assignments[↑i] = unassigned
h3 : ∀ (k : Fin derivedLits.length), k ≠ j1 → k ≠ j2 → (derivedLits.get k).fst.val ≠ ↑i
⊢ ∃ j1 j2 i_gt_zero,
    ↑j1 ≥ 0 ∧
      ↑j2 ≥ 0 ∧
        derivedLits_arr[j1] = (⟨↑i, ⋯⟩, true) ∧
          derivedLits_arr[j2] = (⟨↑i, ⋯⟩, false) ∧
            f'.assignments[↑i] = both ∧
              f.assignments[↑i] = unassigned ∧
                ∀ (k : Fin derivedLits_arr.size), ↑k ≥ 0 → k ≠ j1 → k ≠ j2 → derivedLits_arr[k].fst.val ≠ ↑i