Chances are slight that Julius is a lion. Chances are slight that John grabbed the apple. It is probable that Bernhard is white. It is probably the case that if either 'Bernhard is white' or 'John grabbed the apple' but not both then Brian is yellow. It is highly likely that if 'Bernhard is white' or 'Julius is a lion' or both then Sumit is bored. It is probable that if 'Julius is a lion and Bernhard is white' then Mary dropped the apple.
There is a very good chance that 'Mary dropped the apple and Brian is yellow'.
There is almost no chance that 'Mary dropped the apple and Brian is yellow'.
There is a very good chance that 'Mary dropped the apple and Brian is yellow'.

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

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

  query(conclusion).
  
'Mary dropped the apple and Brian is yellow'.