There is little chance that Greg is green. It is certain that Emily is a sheep. It is highly likely that Julius is a lion. We believe that if either 'Julius is a lion' or 'Emily is a sheep' but not both then Brian is white. It is impossible that if 'Emily is a sheep and Julius is a lion' then Jessica is a mouse. Chances are slight that if 'Julius is a lion' or 'Emily is a sheep' or both then Mary left the milk.
It is certain that 'Julius is a lion' or 'Brian is white' or both.
It is certain that 'Julius is a lion' or 'Brian is white' or both.
It is improbable that 'Julius is a lion' or 'Brian 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
  0.1::factA.
  1.0::factB.
  0.9::factC.
  %hop1
  0.75::factX:-xor(factC,factB).
  0.0::factY:-and(factB,factC).
  0.1::factZ:-or(factC,factB).

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

  query(conclusion).
  
'Julius is a lion' or 'Brian is white' or both.