rw [insertUnit_preserves_size]
n : Nat
assignments0 : Array Assignment
assignments0_size : assignments0.size = n
hd : Literal (PosFin n)
tl : List (Literal (PosFin n))
ih :
  ∀ (rupUnits : Array (Literal (PosFin n))) (assignments : Array Assignment) (assignments_size : assignments.size = n)
    (b : Bool),
    insertUnit_invariant assignments0 assignments0_size rupUnits assignments assignments_size →
      let update_res := List.foldl insertUnit (rupUnits, assignments, b) tl;
      let_fun update_res_size := ⋯;
      insertUnit_invariant assignments0 assignments0_size update_res.fst update_res.snd.fst update_res_size
rupUnits : Array (Literal (PosFin n))
assignments : Array Assignment
assignments_size : assignments.size = n
b : Bool
h0 : insertUnit_invariant assignments0 assignments0_size rupUnits assignments assignments_size
update_res : Array (Literal (PosFin n)) × Array Assignment × Bool := insertUnit (rupUnits, assignments, b) hd
⊢ update_res.snd.fst.size = n
n : Nat
assignments0 : Array Assignment
assignments0_size : assignments0.size = n
hd : Literal (PosFin n)
tl : List (Literal (PosFin n))
ih :
  ∀ (rupUnits : Array (Literal (PosFin n))) (assignments : Array Assignment) (assignments_size : assignments.size = n)
    (b : Bool),
    insertUnit_invariant assignments0 assignments0_size rupUnits assignments assignments_size →
      let update_res := List.foldl insertUnit (rupUnits, assignments, b) tl;
      let_fun update_res_size := ⋯;
      insertUnit_invariant assignments0 assignments0_size update_res.fst update_res.snd.fst update_res_size
rupUnits : Array (Literal (PosFin n))
assignments : Array Assignment
assignments_size : assignments.size = n
b : Bool
h0 : insertUnit_invariant assignments0 assignments0_size rupUnits assignments assignments_size
update_res : Array (Literal (PosFin n)) × Array Assignment × Bool := insertUnit (rupUnits, assignments, b) hd
⊢ assignments.size = n