It is probably the case that John moved to the garden. We believe that Fred is in the school. It is likely that Greg is a lion. It is probably not the case that if either 'Greg is a lion' or 'John moved to the garden' but not both then Julius is white. Chances are about even that if 'John moved to the garden' or 'Fred is in the school' or both then Lily is yellow. It is almost certain that if either 'Greg is a lion' or 'John moved to the garden' but not both then Brian is a rhino.
There is a very good chance that 'Greg is a lion' or 'Lily is yellow' or both.
There is a very good chance that 'Greg is a lion' or 'Lily is yellow' or both.
It is unlikely that 'Greg is a lion' or 'Lily is yellow' 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
  0.7::factA.
  0.75::factB.
  0.7::factC.
  %hop1
  0.25::factX:-xor(factC,factA).
  0.5::factY:-or(factA,factB).
  0.95::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Greg is a lion' or 'Lily is yellow' or both.