There is a better than even chance that Daniel dropped the milk. It is probably not the case that Mary put down the milk. Chances are slight that Bill went to the bedroom. There is almost no chance that if either 'Mary put down the milk' or 'Bill went to the bedroom' but not both then Bernhard is gray. It is highly likely that if 'Mary put down the milk and Daniel dropped the milk' then Jeff moved to the office. It is probably the case that if either 'Daniel dropped the milk' or 'Bill went to the bedroom' but not both then Brian is green.
It is improbable that 'Mary put down the milk and Jeff moved to the office'.
It is improbable that 'Mary put down the milk and Jeff moved to the office'.
There is a very good chance that 'Mary put down the milk and Jeff moved to the office'.

  and(A,B) :- A,B.
  or(A,B) :- A;B.
  nand(A,B) :- not(and(A,B)).
  nor(A,B) :- not(or(A,B)).
  xor(A,B) :- or(A,B), nand(A,B).

  %hop0
  0.6::factA.
  0.25::factB.
  0.1::factC.
  %hop1
  0.02::factX:-xor(factB,factC).
  0.9::factY:-and(factB,factA).
  0.7::factZ:-xor(factA,factC).

  %hop2
  conclusion:-and(factB,factY).

  query(conclusion).
  
'Mary put down the milk and Jeff moved to the office'.