There is a better than even chance that Fred dropped the milk. It is almost certain that Brian is yellow. It is almost certain that Lily is white. It is improbable that if 'Brian is yellow and Fred dropped the milk' then Winona is a mouse. It is certain that if 'Fred dropped the milk' or 'Lily is white' or both then Greg is a rhino. It is impossible that if either 'Fred dropped the milk' or 'Brian is yellow' but not both then Jeff left the apple.
Chances are slight that 'Fred dropped the milk and Greg is a rhino'.
There is a better than even chance that 'Fred dropped the milk and Greg is a rhino'.
Chances are slight that 'Fred dropped the milk and Greg is a rhino'.

  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
  0.6::factA.
  0.95::factB.
  0.95::factC.
  %hop1
  0.1::factX:-and(factB,factA).
  1.0::factY:-or(factA,factC).
  0.0::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Fred dropped the milk and Greg is a rhino'.