module light_increasing_and_decreasing
  depends on increasing_and_decreasing

  sort declarations
    brighten :: increase

    dim :: decrease


  axioms
    affected_property(X) = brightness if instance(X, brightness).

    false if instance(X, brighten),
             from_value(X, FV),
             -instance(FV, brightness_value).

    false if instance(X, brighten),
             -defined_base(X).

    false if instance(X, brighten),
             base(X, B),
             -instance(B, tangible_entity).

    impossible occurs(X) if instance(X, brighten),
                            from_value(X, FV),
                            base(X, B),
                            -breakability(B, FV).


    affected_property(X) = brightness if instance(X, dim).

    false if instance(X, dim),
             from_value(X, FV),
             -instance(FV, brightness_value).

    false if instance(X, dim),
             -defined_base(X).

    false if instance(X, dim),
             base(X, B),
             -instance(B, tangible_entity).

    impossible occurs(X) if instance(X, dim),
                            from_value(X, FV),
                            base(X, B),
                            -breakability(B, FV).