simp only [Array.getElem_eq_data_get, not_true] at h3
n : Nat
f : DefaultFormula n
f_assignments_size : f.assignments.size = n
rupHints : Array Nat
f'_assignments_size : (f.performRupCheck rupHints).fst.assignments.size = n
derivedLits : List (Literal (PosFin n))
derivedLits_satisfies_invariant :
  f.derivedLits_invariant f_assignments_size (f.performRupCheck rupHints).fst.assignments f'_assignments_size
    derivedLits
derivedLits_arr : Array (Literal (PosFin n))
derivedLits_arr_def : derivedLits_arr = { data := derivedLits }
i j : Fin derivedLits_arr.size
i_ne_j : i ≠ j
li : Literal (PosFin n) := derivedLits_arr[i]
li_in_derivedLits : li ∈ derivedLits
i_in_bounds : ↑i < derivedLits.length
j_in_bounds : ↑j < derivedLits.length
k : Fin derivedLits.length
left✝² : (derivedLits.get k).fst.val = ↑⟨li.fst.val, ⋯⟩
left✝¹ :
  (f.performRupCheck rupHints).fst.assignments[↑⟨li.fst.val, ⋯⟩] =
    addAssignment (derivedLits.get k).snd f.assignments[↑⟨li.fst.val, ⋯⟩]
left✝ : ¬hasAssignment (derivedLits.get k).snd f.assignments[↑⟨li.fst.val, ⋯⟩] = true
k_eq_i : ↑k = ↑i
j_ne_k : ⟨↑j, j_in_bounds⟩ ≠ k
li_eq_lj : { data := derivedLits }[↑i] = { data := derivedLits }[↑j]
h3 : ¬(derivedLits.get ⟨↑j, j_in_bounds⟩).fst.val = { data := derivedLits }[↑j].fst.val
⊢ False
no goals