It is highly likely that Bernhard is gray. There is almost no chance that Jessica is a mouse. Chances are slight that Mary went to the office. It is probably not the case that if 'Jessica is a mouse' or 'Bernhard is gray' or both then Julius is a lion. There is almost no chance that if 'Bernhard is gray' or 'Jessica is a mouse' or both then John is in the garden. It is highly likely that if 'Mary went to the office and Jessica is a mouse' then Brian is a frog.
It is highly likely that 'Bernhard is gray' or 'Jessica is a mouse' or both.
It is highly likely that 'Bernhard is gray' or 'Jessica is a mouse' or both.
There is almost no chance that 'Bernhard is gray' or 'Jessica is a mouse' or both.

  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
  0.9::factA.
  0.02::factB.
  0.1::factC.
  %hop1
  0.25::factX:-or(factB,factA).
  0.02::factY:-or(factA,factB).
  0.9::factZ:-and(factC,factB).

  %hop2
  conclusion:-or(factA,factB).

  query(conclusion).
  
'Bernhard is gray' or 'Jessica is a mouse' or both.