It is highly unlikely that Bernhard is a frog. It is highly unlikely that Brian is white. It is impossible that Bill went to the garden. It is almost certain that if 'Bill went to the garden and Bernhard is a frog' then John discarded the apple. There is a very good chance that if either 'Bernhard is a frog' or 'Bill went to the garden' but not both then Julius is a lion. We doubt that if 'Bernhard is a frog' or 'Bill went to the garden' or both then Greg is yellow.
It is highly likely that 'Julius is a lion' or 'Greg is yellow' or both.
It is highly unlikely that 'Julius is a lion' or 'Greg is yellow' or both.
It is highly likely that 'Julius is a lion' or 'Greg is yellow' or 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
  0.05::factA.
  0.05::factB.
  0.0::factC.
  %hop1
  0.95::factX:-and(factC,factA).
  0.8::factY:-xor(factA,factC).
  0.2::factZ:-or(factA,factC).

  %hop2
  conclusion:-or(factY,factZ).

  query(conclusion).
  
'Julius is a lion' or 'Greg is yellow' or both.