It is highly unlikely that Bernhard is white. There is a better than even chance that Mary got the milk. It is likely that Greg is a rhino. It is almost certain that if either 'Bernhard is white' or 'Greg is a rhino' but not both then Jessica is a mouse. We doubt that if 'Mary got the milk and Greg is a rhino' then Brian is gray. There is almost no chance that if either 'Bernhard is white' or 'Greg is a rhino' but not both then Jason is thirsty.
There is almost no chance that 'Jessica is a mouse and Jason is thirsty'.
There is almost no chance that 'Jessica is a mouse and Jason is thirsty'.
It is highly likely that 'Jessica is a mouse and Jason is thirsty'.

  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
  0.05::factA.
  0.6::factB.
  0.7::factC.
  %hop1
  0.95::factX:-xor(factA,factC).
  0.2::factY:-and(factB,factC).
  0.02::factZ:-xor(factA,factC).

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

  query(conclusion).
  
'Jessica is a mouse and Jason is thirsty'.