message: Make primitive construction more succinct
diff: @@ -57,22 +57,17 @@ impl<'arena> RigidEnv<'arena> {
  let format_type = shared(Arc::new(Value::prim(Prim::FormatType, [])));
  let array_type = |index_type: Prim| {
  - Arc::new(Value::FunType(
  - None,
  - Arc::new(Value::prim(index_type, [])),
  - close(Term::FunType(None, &Term::Universe, &Term::Universe)),
  - ))
  + let index_type = Arc::new(Value::prim(index_type, []));
  + let output_type = close(Term::FunType(None, &Term::Universe, &Term::Universe));
  +
  + Arc::new(Value::FunType(None, index_type, output_type))
  };
  let format_array = |index_type: Prim| {
  - Arc::new(Value::FunType(
  - None,
  - Arc::new(Value::prim(index_type, [])),
  - close(Term::FunType(
  - None,
  - &Term::Prim(Prim::FormatType),
  - &Term::Prim(Prim::FormatType),
  - )),
  - ))
  + let index_type = Arc::new(Value::prim(index_type, []));
  + let format_type = &Term::Prim(Prim::FormatType);
  + let output_type = close(Term::FunType(None, format_type, format_type));
  +
  + Arc::new(Value::FunType(None, index_type, output_type))
  };
  let mut define_prim = |prim: Prim, r#type| {
  