It is unlikely that Mary got the football. It is likely that Lily is a frog. It is almost certain that Greg is a rhino. It is almost certain that if 'Lily is a frog' or 'Mary got the football' or both then John left the football. It is unlikely that if either 'Lily is a frog' or 'Mary got the football' but not both then Brian is white. We believe that if either 'Lily is a frog' or 'Mary got the football' but not both then Bernhard is green.
It is probable that either 'John left the football' or 'Lily is a frog' but not both.
It is improbable that either 'John left the football' or 'Lily is a frog' but not both.
It is probable that either 'John left the football' or 'Lily is a frog' but not both.

  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.
  0.95::factC.
  %hop1
  0.95::factX:-or(factB,factA).
  0.2::factY:-xor(factB,factA).
  0.75::factZ:-xor(factB,factA).

  %hop2
  conclusion:-xor(factX,factB).

  query(conclusion).
  
Either 'John left the football' or 'Lily is a frog' but not both.