It is almost certain that Bernhard is white. We doubt that Brian is a rhino. It is likely that Lily is a swan. Chances are about even that if 'Brian is a rhino' or 'Bernhard is white' or both then Greg is a frog. There is a very good chance that if 'Brian is a rhino' or 'Bernhard is white' or both then Sandra dropped the milk. We believe that if 'Bernhard is white' or 'Lily is a swan' or both then John left the football.
It is almost certain that 'Greg is a frog' or 'Bernhard is white' or both.
It is almost certain that 'Greg is a frog' or 'Bernhard is white' or both.
It is highly unlikely that 'Greg is a frog' or 'Bernhard is white' 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
  0.95::factA.
  0.2::factB.
  0.7::factC.
  %hop1
  0.5::factX:-or(factB,factA).
  0.8::factY:-or(factB,factA).
  0.75::factZ:-or(factA,factC).

  %hop2
  conclusion:-or(factX,factA).

  query(conclusion).
  
'Greg is a frog' or 'Bernhard is white' or both.