There is a very good chance that John put down the apple. It is probable that Daniel got the football. It is almost certain that Lily is a rhino. It is highly unlikely that if 'Daniel got the football and Lily is a rhino' then Jeff discarded the milk. We doubt that if either 'Daniel got the football' or 'John put down the apple' but not both then Greg is a frog. It is highly likely that if 'Daniel got the football' or 'Lily is a rhino' or both then Bernhard is green.
It is highly likely that either 'Jeff discarded the milk' or 'Lily is a rhino' but not both.
It is highly likely that either 'Jeff discarded the milk' or 'Lily is a rhino' but not both.
It is highly unlikely that either 'Jeff discarded the milk' or 'Lily is a rhino' but not both.

  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
  0.8::factA.
  0.7::factB.
  0.95::factC.
  %hop1
  0.05::factX:-and(factB,factC).
  0.2::factY:-xor(factB,factA).
  0.9::factZ:-or(factB,factC).

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

  query(conclusion).
  
Either 'Jeff discarded the milk' or 'Lily is a rhino' but not both.