It is almost certain that Julius is yellow. It is unlikely that Brian is white. It is highly likely that John took the milk. Chances are about even that if 'John took the milk' or 'Julius is yellow' or both then Jessica is a wolf. It is almost certain that if either 'John took the milk' or 'Julius is yellow' but not both then Gertrude is a sheep. There is almost no chance that if 'Julius is yellow' or 'Brian is white' or both then Jason is thirsty.
It is highly unlikely that 'Julius is yellow and John took the milk'.
It is highly likely that 'Julius is yellow and John took the milk'.
It is highly unlikely that 'Julius is yellow and John took the milk'.

  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
  0.95::factA.
  0.2::factB.
  0.9::factC.
  %hop1
  0.5::factX:-or(factC,factA).
  0.95::factY:-xor(factC,factA).
  0.02::factZ:-or(factA,factB).

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

  query(conclusion).
  
'Julius is yellow and John took the milk'.