It is improbable that Greg is a frog. There is a very good chance that Julius is a swan. There is little chance that John moved to the office. It is certain that if 'John moved to the office and Greg is a frog' then Lily is gray. It is probably the case that if 'Greg is a frog and John moved to the office' then Jessica is a cat. It is certain that if 'Julius is a swan' or 'Greg is a frog' or both then Brian is a lion.
Chances are slight that 'Lily is gray' or 'Julius is a swan' or both.
There is a very good chance that 'Lily is gray' or 'Julius is a swan' or both.
Chances are slight that 'Lily is gray' or 'Julius is a swan' 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.
  0.8::factB.
  0.1::factC.
  %hop1
  1.0::factX:-and(factC,factA).
  0.7::factY:-and(factA,factC).
  1.0::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Lily is gray' or 'Julius is a swan' or both.