It is probably not the case that Greg is white. Chances are about even that Jessica is a cat. There is almost no chance that Lily is a frog. It is probably the case that if either 'Greg is white' or 'Jessica is a cat' but not both then Jason is bored. We doubt that if 'Lily is a frog' or 'Greg is white' or both then Mary left the apple. It is almost certain that if 'Jessica is a cat' or 'Greg is white' or both then Julius is a swan.
There is almost no chance that 'Jason is bored' or 'Greg is white' or both.
Chances are about even that 'Jason is bored' or 'Greg is white' or both.
There is almost no chance that 'Jason is bored' 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.
  0.5::factB.
  0.02::factC.
  %hop1
  0.7::factX:-xor(factA,factB).
  0.2::factY:-or(factC,factA).
  0.95::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Jason is bored' or 'Greg is white' or both.