Chances are slight that Greg is gray. It is probably the case that Julius is white. There is a better than even chance that Bernhard is a frog. It is unlikely that if 'Julius is white' or 'Bernhard is a frog' or both then Brian is a rhino. We doubt that if 'Bernhard is a frog' or 'Greg is gray' or both then John went to the bedroom. It is probably not the case that if either 'Greg is gray' or 'Julius is white' but not both then Mary got the apple.
It is highly likely that 'Julius is white and John went to the bedroom'.
Chances are slight that 'Julius is white and John went to the bedroom'.
It is highly likely that 'Julius is white and John went to the bedroom'.

  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.
  0.7::factB.
  0.6::factC.
  %hop1
  0.2::factX:-or(factB,factC).
  0.2::factY:-or(factC,factA).
  0.25::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Julius is white and John went to the bedroom'.