apply Or.inl
n : Nat
f : DefaultFormula n
f_readyForRupAdd : f.readyForRupAdd
units : List (Literal (PosFin n))
hsize : f.assignments.size = n
i : Fin n
⊢ (∀ (j : Fin f.rupUnits.size), ¬f.rupUnits[↑j].fst.val = ↑i) ∨
    (∃ j b,
        (∃ x, f.rupUnits[↑j] = (⟨↑i, ⋯⟩, b)) ∧
          f.assignments[↑i] = addAssignment b f.assignments[↑i] ∧
            hasAssignment b f.assignments[↑i] = false ∧
              ∀ (k : Fin f.rupUnits.size), ¬k = j → ¬f.rupUnits[↑k].fst.val = ↑i) ∨
      ∃ j1 j2 i_gt_zero,
        f.rupUnits[↑j1] = (⟨↑i, ⋯⟩, true) ∧
          f.rupUnits[↑j2] = (⟨↑i, ⋯⟩, false) ∧
            f.assignments[↑i] = both ∧
              f.assignments[↑i] = unassigned ∧
                ∀ (k : Fin f.rupUnits.size), ¬k = j1 → ¬k = j2 → ¬f.rupUnits[↑k].fst.val = ↑i
case h
n : Nat
f : DefaultFormula n
f_readyForRupAdd : f.readyForRupAdd
units : List (Literal (PosFin n))
hsize : f.assignments.size = n
i : Fin n
⊢ ∀ (j : Fin f.rupUnits.size), ¬f.rupUnits[↑j].fst.val = ↑i