It is probably the case that John dropped the milk. It is probably the case that Jason is bored. There is a better than even chance that Mary moved to the garden. It is likely that if either 'John dropped the milk' or 'Mary moved to the garden' but not both then Greg is a swan. We believe that if 'Mary moved to the garden' or 'Jason is bored' or both then Emily is a mouse. We doubt that if 'John dropped the milk and Jason is bored' then Julius is a swan.
It is probably not the case that either 'Jason is bored' or 'Emily is a mouse' but not both.
It is probably not the case that either 'Jason is bored' or 'Emily is a mouse' but not both.
It is likely that either 'Jason is bored' or 'Emily is a mouse' 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
  0.7::factA.
  0.7::factB.
  0.6::factC.
  %hop1
  0.7::factX:-xor(factA,factC).
  0.75::factY:-or(factC,factB).
  0.2::factZ:-and(factA,factB).

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

  query(conclusion).
  
Either 'Jason is bored' or 'Emily is a mouse' but not both.