It is likely that Jessica is a mouse. There is almost no chance that Sandra left the football. We believe that Julius is yellow. It is certain that if 'Jessica is a mouse' or 'Sandra left the football' or both then Brian is white. It is highly unlikely that if 'Julius is yellow and Sandra left the football' then Greg is a rhino. It is unlikely that if either 'Sandra left the football' or 'Jessica is a mouse' but not both then Mary grabbed the milk.
There is a better than even chance that 'Mary grabbed the milk and Brian is white'.
It is improbable that 'Mary grabbed the milk and Brian is white'.
There is a better than even chance that 'Mary grabbed the milk and Brian is white'.

  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.
  0.02::factB.
  0.75::factC.
  %hop1
  1.0::factX:-or(factA,factB).
  0.05::factY:-and(factC,factB).
  0.2::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Mary grabbed the milk and Brian is white'.