Chances are about even that Emily is a mouse. Chances are slight that Mary discarded the milk. There is little chance that John grabbed the apple. It is impossible that if either 'Emily is a mouse' or 'Mary discarded the milk' but not both then Antoine is thirsty. It is almost certain that if 'Emily is a mouse and John grabbed the apple' then Greg is a swan. There is a better than even chance that if either 'Emily is a mouse' or 'Mary discarded the milk' but not both then Bernhard is yellow.
It is probably the case that 'Mary discarded the milk' or 'John grabbed the apple' or both.
We doubt that 'Mary discarded the milk' or 'John grabbed the apple' or both.
It is probably the case that 'Mary discarded the milk' or 'John grabbed the apple' or 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
  0.5::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.0::factX:-xor(factA,factB).
  0.95::factY:-and(factA,factC).
  0.6::factZ:-xor(factA,factB).

  %hop2
  conclusion:-or(factB,factC).

  query(conclusion).
  
'Mary discarded the milk' or 'John grabbed the apple' or both.