It is probable that Bill went to the garden. Chances are slight that Mary dropped the milk. There is almost no chance that Julius is a lion. We doubt that if 'Mary dropped the milk' or 'Bill went to the garden' or both then Brian is a rhino. It is unlikely that if 'Bill went to the garden and Mary dropped the milk' then Greg is yellow. It is almost certain that if either 'Bill went to the garden' or 'Mary dropped the milk' but not both then Winona is a mouse.
It is likely that 'Julius is a lion and Brian is a rhino'.
It is impossible that 'Julius is a lion and Brian is a rhino'.
It is likely that 'Julius is a lion 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
  0.7::factA.
  0.1::factB.
  0.02::factC.
  %hop1
  0.2::factX:-or(factB,factA).
  0.2::factY:-and(factA,factB).
  0.95::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Julius is a lion and Brian is a rhino'.