doc-src/IsarAdvanced/Codegen/Thy/examples/bool1.ML
author haftmann
Fri, 03 Nov 2006 14:22:33 +0100
changeset 21147 737a94f047e3
child 21172 eea3c9048c7a
permissions -rw-r--r--
continued tutorial

structure ROOT = 
struct

structure HOL = 
struct

datatype boola = True | False;

fun nota False = True
  | nota True = False;

fun op_conj y True = y
  | op_conj x False = False
  | op_conj True ya = ya
  | op_conj False xa = False;

end; (*struct HOL*)

structure IntDef = 
struct

datatype nat = Zero_nat | Succ_nat of nat;

fun less_nat Zero_nat (Succ_nat n) = HOL.True
  | less_nat na Zero_nat = HOL.False
  | less_nat (Succ_nat m) (Succ_nat nb) = less_nat m nb;

fun less_eq_nat m n = HOL.nota (less_nat n m);

end; (*struct IntDef*)

structure Codegen = 
struct

fun in_interval (k, l) n =
  HOL.op_conj (IntDef.less_eq_nat k n) (IntDef.less_eq_nat n l);

end; (*struct Codegen*)

end; (*struct ROOT*)