It is likely that Greg is a rhino. It is probable that Lily is a swan. It is highly unlikely that Daniel dropped the apple. It is probably the case that if 'Lily is a swan and Greg is a rhino' then Mary went to the kitchen. It is unlikely that if 'Lily is a swan' or 'Greg is a rhino' or both then Bernhard is a frog. Chances are slight that if either 'Daniel dropped the apple' or 'Greg is a rhino' but not both then Brian is a lion.
It is improbable that 'Lily is a swan and Bernhard is a frog'.
It is improbable that 'Lily is a swan and Bernhard is a frog'.
It is almost certain that 'Lily is a swan and Bernhard is a frog'.

  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.
  0.7::factB.
  0.05::factC.
  %hop1
  0.7::factX:-and(factB,factA).
  0.2::factY:-or(factB,factA).
  0.1::factZ:-xor(factC,factA).

  %hop2
  conclusion:-and(factB,factY).

  query(conclusion).
  
'Lily is a swan and Bernhard is a frog'.