It is improbable that Bernhard is a frog. We doubt that Sumit is thirsty. It is highly likely that Greg is a rhino. It is almost certain that if either 'Bernhard is a frog' or 'Sumit is thirsty' but not both then Lily is green. It is likely that if 'Greg is a rhino' or 'Sumit is thirsty' or both then Mary got the football. There is a very good chance that if 'Bernhard is a frog and Sumit is thirsty' then Brian is a swan.
It is highly likely that 'Greg is a rhino' or 'Lily is green' or both.
It is highly likely that 'Greg is a rhino' or 'Lily is green' or both.
It is highly unlikely that 'Greg is a rhino' or 'Lily is green' 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
  0.1::factA.
  0.2::factB.
  0.9::factC.
  %hop1
  0.95::factX:-xor(factA,factB).
  0.7::factY:-or(factC,factB).
  0.8::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Greg is a rhino' or 'Lily is green' or both.