Documentation around policies is confusing. I don't know when my policy's function would be called. I only know which Outcome's function will call it.
That's the only way your policy's function is ever called, by the Outcome function documented.
From this page[1], I understand that my policy's function will do the check to see if value is valid.
But another page[2] will tell me that all_narrow's functions will call _ub() **undiscriminately**. Does it mean that the checks are performed internally by Outcome and policy's functions are only called conditionally?
Yes, I see the problem on [2]. It doesn't say that `_ub()` is called on invalid observation only. I'll fix that now. Thanks for the feedback. Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/