It is unlikely that Winona is a sheep. It is likely that Mary left the football. There is almost no chance that John picked up the milk. It is almost certain that if either 'Winona is a sheep' or 'John picked up the milk' but not both then Greg is gray. It is impossible that if either 'Mary left the football' or 'Winona is a sheep' but not both then Brian is yellow. It is certain that if 'John picked up the milk' or 'Mary left the football' or both then Julius is a frog.
There is a better than even chance that 'Mary left the football and Brian is yellow'.
It is impossible that 'Mary left the football and Brian is yellow'.
There is a better than even chance that 'Mary left the football and Brian is yellow'.

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

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

  query(conclusion).
  
'Mary left the football and Brian is yellow'.