There is little chance that Julius is gray. There is a very good chance that Winona is a wolf. It is improbable that Lily is a swan. It is certain that if 'Julius is gray and Winona is a wolf' then Fred put down the apple. It is impossible that if 'Julius is gray' or 'Lily is a swan' or both then Brian is a rhino. There is a better than even chance that if 'Julius is gray' or 'Lily is a swan' or both then Mary went to the kitchen.
There is a very good chance that 'Fred put down the apple and Brian is a rhino'.
It is impossible that 'Fred put down the apple and Brian is a rhino'.
There is a very good chance that 'Fred put down the apple and Brian is a rhino'.

  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
  0.1::factA.
  0.8::factB.
  0.1::factC.
  %hop1
  1.0::factX:-and(factA,factB).
  0.0::factY:-or(factA,factC).
  0.6::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Fred put down the apple and Brian is a rhino'.