Chances are slight that Julius is a lion. It is impossible that Brian is white. There is almost no chance that Greg is yellow. It is likely that if 'Greg is yellow and Julius is a lion' then Lily is a rhino. It is unlikely that if 'Brian is white' or 'Julius is a lion' or both then John got the apple. It is probable that if either 'Greg is yellow' or 'Brian is white' but not both then Mary dropped the milk.
It is probably the case that 'Greg is yellow' or 'John got the apple' or both.
It is highly unlikely that 'Greg is yellow' or 'John got the apple' or both.
It is probably the case that 'Greg is yellow' or 'John got the apple' 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.
  0.0::factB.
  0.02::factC.
  %hop1
  0.7::factX:-and(factC,factA).
  0.2::factY:-or(factB,factA).
  0.7::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'Greg is yellow' or 'John got the apple' or both.