It is unlikely that Fred went to the garden. It is probably the case that Emily is a cat. It is probably the case that Greg is a rhino. It is certain that if 'Greg is a rhino' or 'Fred went to the garden' or both then Lily is a lion. It is unlikely that if 'Fred went to the garden and Greg is a rhino' then John left the milk. There is a very good chance that if 'Fred went to the garden and Emily is a cat' then Gertrude is a mouse.
There is almost no chance that 'Lily is a lion and John left the milk'.
There is almost no chance that 'Lily is a lion and John left the milk'.
We believe that 'Lily is a lion and John left 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
  0.2::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  1.0::factX:-or(factC,factA).
  0.2::factY:-and(factA,factC).
  0.8::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Lily is a lion and John left the milk'.