It is impossible that Julius is a rhino. It is likely that Bernhard is green. There is almost no chance that John dropped the apple. It is highly likely that if 'John dropped the apple' or 'Julius is a rhino' or both then Brian is yellow. It is highly likely that if either 'Bernhard is green' or 'John dropped the apple' but not both then Greg is a swan. It is impossible that if 'John dropped the apple' or 'Julius is a rhino' or both then Jeff put down the milk.
It is impossible that 'Julius is a rhino and Jeff put down the milk'.
It is impossible that 'Julius is a rhino and Jeff put down the milk'.
There is a very good chance that 'Julius is a rhino and Jeff put down 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
  0.0::factA.
  0.7::factB.
  0.02::factC.
  %hop1
  0.9::factX:-or(factC,factA).
  0.9::factY:-xor(factB,factC).
  0.0::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Julius is a rhino and Jeff put down the milk'.