We doubt that Jessica is a cat. We doubt that Jeff dropped the apple. It is improbable that Lily is a frog. It is improbable that if 'Lily is a frog' or 'Jessica is a cat' or both then John left the apple. There is a very good chance that if 'Jeff dropped the apple' or 'Jessica is a cat' or both then Bernhard is green. There is little chance that if 'Jessica is a cat and Lily is a frog' then Julius is a rhino.
It is almost certain that 'John left the apple' or 'Lily is a frog' or both.
There is little chance that 'John left the apple' or 'Lily is a frog' or both.
It is almost certain that 'John left the apple' or 'Lily is a frog' 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
  0.2::factA.
  0.2::factB.
  0.1::factC.
  %hop1
  0.1::factX:-or(factC,factA).
  0.8::factY:-or(factB,factA).
  0.1::factZ:-and(factA,factC).

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

  query(conclusion).
  
'John left the apple' or 'Lily is a frog' or both.