structure ROOT =
struct
structure HOL =
struct
datatype boola = True | False;
fun op_and y True = y
| op_and x False = False
| op_and True y = y
| op_and False x = False;
end; (*struct HOL*)
structure Nat =
struct
datatype nat = Zero_nat | Suc of nat;
fun less_nat n (Suc m) = less_eq_nat n m
| less_nat n Zero_nat = HOL.False
and less_eq_nat (Suc n) m = less_nat n m
| less_eq_nat Zero_nat m = HOL.True;
end; (*struct Nat*)
structure Codegen =
struct
fun in_interval (k, l) n =
HOL.op_and (Nat.less_eq_nat k n) (Nat.less_eq_nat n l);
end; (*struct Codegen*)
end; (*struct ROOT*)