module { export = [main], features = [chr] }
import "Prelude"

ruleset Foo where
    constraint Foo Integer

main = ()
  where
    foo = createFoo
    include Foo foo
    
    when Foo ?x
    then print ?x
    
    when True
    then Foo 2
    
    when Foo ?x
         ?x < 5
    then Foo (?x + 1)
--
2
3
4
5
()