1% { q, r, not p }
    2% Rules for p, r and q.1 are both ordinary and OLON: even loop through q.2, odd
    3% loop through q.1.
    4
    5p :- not q.
    6q :- not r.
    7r :- not p.
    8q :- not p.
    9
   10% #compute 1 { q }.
   11:- not