There is almost no chance that Emily is a mouse. Chances are about even that Bernhard is gray. Chances are about even that Lily is a frog. It is impossible that if 'Lily is a frog and Emily is a mouse' then Winona is a wolf. There is little chance that if 'Lily is a frog' or 'Emily is a mouse' or both then John left the football. It is improbable that if either 'Bernhard is gray' or 'Lily is a frog' but not both then Greg is a swan.
It is highly unlikely that either 'Winona is a wolf' or 'John left the football' but not both.
It is highly unlikely that either 'Winona is a wolf' or 'John left the football' but not both.
There is a better than even chance that either 'Winona is a wolf' or 'John left the football' 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
  0.02::factA.
  0.5::factB.
  0.5::factC.
  %hop1
  0.0::factX:-and(factC,factA).
  0.1::factY:-or(factC,factA).
  0.1::factZ:-xor(factB,factC).

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

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