We believe that Lily is white. It is impossible that Emily is a mouse. There is little chance that Brian is a swan. It is probably the case that if 'Emily is a mouse and Lily is white' then John put down the milk. It is unlikely that if 'Lily is white' or 'Brian is a swan' or both then Winona is a wolf. It is likely that if 'Emily is a mouse' or 'Lily is white' or both then Sandra left the apple.
It is almost certain that 'John put down the milk and Brian is a swan'.
It is impossible that 'John put down the milk and Brian is a swan'.
It is almost certain that 'John put down the milk and Brian is a swan'.

  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
  0.75::factA.
  0.0::factB.
  0.1::factC.
  %hop1
  0.7::factX:-and(factB,factA).
  0.2::factY:-or(factA,factC).
  0.7::factZ:-or(factB,factA).

  %hop2
  conclusion:-and(factX,factC).

  query(conclusion).
  
'John put down the milk and Brian is a swan'.