QUERY:

I would like to know if
     Bob goes to the opera on the day D.

USER PREDICATES:
Bob goes to the opera on A, a day, if
     Bob does not stay at home on A.

'home' holds (for A), if
     there is no evidence that Bob goes to the opera on A, a day.
'home' holds (for monday).

DUAL RULES:
there is no evidence that Bob goes to the opera on A, a day, if
     'rule 1' holds (for A).

'rule 1' holds (for A), if
     'home' holds (for A).

Bob does not stay at home on A, if
     'rule 1' holds (for A) and
     'rule 2' holds (for A).

'rule 1' holds (for A), if
     Bob goes to the opera on A, a day.

'rule 2' holds (for A), if
     A is not equal monday.


GLOBAL CONSTRAINTS:
The global constraints hold.