It is probably not the case that Brian is a frog. Chances are slight that Greg is white. Chances are slight that Bernhard is white. It is impossible that if 'Greg is white and Brian is a frog' then Jason is tired. It is unlikely that if either 'Bernhard is white' or 'Greg is white' but not both then Lily is a rhino. There is little chance that if either 'Bernhard is white' or 'Brian is a frog' but not both then John left the apple.
There is a better than even chance that 'Lily is a rhino' or 'Greg is white' or both.
There is little chance that 'Lily is a rhino' or 'Greg is white' or both.
There is a better than even chance that 'Lily is a rhino' or 'Greg 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
  0.25::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.0::factX:-and(factB,factA).
  0.2::factY:-xor(factC,factB).
  0.1::factZ:-xor(factC,factA).

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

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