It is improbable that Julius is a frog. It is certain that Brian is a rhino. Chances are about even that Greg is gray. There is little chance that if 'Julius is a frog and Greg is gray' then John dropped the milk. We believe that if 'Julius is a frog' or 'Brian is a rhino' or both then Lily is yellow. It is highly likely that if 'Julius is a frog' or 'Greg is gray' or both then Jessica is a mouse.
Chances are about even that 'Jessica is a mouse' or 'Julius is a frog' or both.
Chances are about even that 'Jessica is a mouse' or 'Julius is a frog' or both.
It is certain that 'Jessica is a mouse' or 'Julius 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
  0.1::factA.
  1.0::factB.
  0.5::factC.
  %hop1
  0.1::factX:-and(factA,factC).
  0.75::factY:-or(factA,factB).
  0.9::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Jessica is a mouse' or 'Julius is a frog' or both.