It is almost certain that Fred moved to the office. It is probably the case that Lily is a swan. It is unlikely that John took the milk. There is a better than even chance that if either 'Fred moved to the office' or 'Lily is a swan' but not both then Brian is a rhino. There is a very good chance that if either 'John took the milk' or 'Lily is a swan' but not both then Mary dropped the apple. It is highly likely that if either 'Fred moved to the office' or 'John took the milk' but not both then Greg is yellow.
It is unlikely that either 'Fred moved to the office' or 'John took the milk' but not both.
We believe that either 'Fred moved to the office' or 'John took the milk' but not both.
It is unlikely that either 'Fred moved to the office' or 'John took the milk' 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
  0.95::factA.
  0.7::factB.
  0.2::factC.
  %hop1
  0.6::factX:-xor(factA,factB).
  0.8::factY:-xor(factC,factB).
  0.9::factZ:-xor(factA,factC).

  %hop2
  conclusion:-xor(factA,factC).

  query(conclusion).
  
Either 'Fred moved to the office' or 'John took the milk' but not both.