doc-src/IsarAdvanced/Codegen/Thy/examples/bool_infix.ML

 structure Nat = 
 struct
 
-datatype nat = Zero_nat | Suc of nat;
+datatype nat = Suc of nat | Zero_nat;
 
 fun less_nat n (Suc m) = less_eq_nat n m
   | less_nat n Zero_nat = false
 and less_eq_nat (Suc n) m = less_nat n m
   | less_eq_nat Zero_nat m = true;