We doubt that John picked up the apple. Chances are slight that Bernhard is a rhino. It is highly unlikely that Jeff discarded the milk. It is probable that if either 'John picked up the apple' or 'Jeff discarded the milk' but not both then Emily is a sheep. There is little chance that if either 'Bernhard is a rhino' or 'Jeff discarded the milk' but not both then Lily is yellow. There is little chance that if 'Jeff discarded the milk and Bernhard is a rhino' then Winona is a cat.
It is probable that 'Emily is a sheep and Bernhard is a rhino'.
There is almost no chance that 'Emily is a sheep and Bernhard is a rhino'.
It is probable that 'Emily is a sheep and Bernhard 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
  0.2::factA.
  0.1::factB.
  0.05::factC.
  %hop1
  0.7::factX:-xor(factA,factC).
  0.1::factY:-xor(factB,factC).
  0.1::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Emily is a sheep and Bernhard is a rhino'.