rw [Array.foldl_eq_foldl_data]
n : Nat
f : DefaultFormula n
rupHints : Array Nat
⊢ (Array.foldl (confirmRupHint f.clauses) (f.assignments, [], false, false) rupHints 0).fst.size = f.assignments.size
n : Nat
f : DefaultFormula n
rupHints : Array Nat
⊢ (List.foldl (confirmRupHint f.clauses) (f.assignments, [], false, false) rupHints.data).fst.size = f.assignments.size