- Explicitely passed pred_subset_eq and pred_equals_eq as an argument to the
to_set and to_pred attributes, because it is no longer applied automatically
- Manually applied predicate1I in proof of accp_subset, because it is no longer
part of the claset
- Replaced psubset_def by less_le
structure Nat =
struct
datatype nat = Suc of nat | Zero_nat;
end; (*struct Nat*)
structure Codegen =
struct
type 'a null = {null : 'a};
fun null (A_:'a null) = #null A_;
fun head A_ (x :: xs) = x
| head A_ [] = null A_;
val null_option : 'a option = NONE;
fun null_optiona () = {null = null_option} : ('a option) null;
val dummy : Nat.nat option =
head (null_optiona ()) [SOME (Nat.Suc Nat.Zero_nat), NONE];
end; (*struct Codegen*)