It is likely that Lily is a lion. There is a very good chance that Bernhard is white. We believe that Jeff left the apple. It is highly likely that if 'Bernhard is white' or 'Lily is a lion' or both then Gertrude is a cat. We believe that if 'Lily is a lion and Jeff left the apple' then Brian is a rhino. It is certain that if either 'Lily is a lion' or 'Jeff left the apple' but not both then John put down the milk.
It is highly likely that 'Jeff left the apple and John put down the milk'.
It is probably not the case that 'Jeff left the apple and John put down the milk'.
It is highly likely that 'Jeff left the apple and John put down the milk'.

  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.
  0.8::factB.
  0.75::factC.
  %hop1
  0.9::factX:-or(factB,factA).
  0.75::factY:-and(factA,factC).
  1.0::factZ:-xor(factA,factC).

  %hop2
  conclusion:-and(factC,factZ).

  query(conclusion).
  
'Jeff left the apple and John put down the milk'.