simp only at derivedLits_satisfies_invariant
n : Nat
f : DefaultFormula n
f_assignments_size : f.assignments.size = n
rupHints : Array Nat
f' : DefaultFormula n := (f.performRupCheck rupHints).fst
f'_def : f' = (f.performRupCheck rupHints).fst
f'_assignments_size : f'.assignments.size = n
derivedLits_satisfies_invariant :
  let rupCheckRes := f.performRupCheck rupHints;
  f.derivedLits_invariant f_assignments_size rupCheckRes.fst.assignments f'_assignments_size rupCheckRes.snd.fst
⊢ List.foldl clearUnit (f.performRupCheck rupHints).fst.assignments (f.performRupCheck rupHints).snd.fst = f.assignments
n : Nat
f : DefaultFormula n
f_assignments_size : f.assignments.size = n
rupHints : Array Nat
f' : DefaultFormula n := (f.performRupCheck rupHints).fst
f'_def : f' = (f.performRupCheck rupHints).fst
f'_assignments_size : f'.assignments.size = n
derivedLits_satisfies_invariant :
  f.derivedLits_invariant f_assignments_size (f.performRupCheck rupHints).fst.assignments f'_assignments_size
    (f.performRupCheck rupHints).snd.fst
⊢ List.foldl clearUnit (f.performRupCheck rupHints).fst.assignments (f.performRupCheck rupHints).snd.fst = f.assignments