It is probably the case that Julius is green. It is improbable that Mary went to the bedroom. It is impossible that Bernhard is white. There is little chance that if 'Mary went to the bedroom' or 'Bernhard is white' or both then Sandra dropped the apple. It is probably not the case that if 'Julius is green and Bernhard is white' then Jason is tired. It is likely that if either 'Bernhard is white' or 'Julius is green' but not both then Lily is a lion.
It is probably the case that either 'Sandra dropped the apple' or 'Julius is green' but not both.
It is probably the case that either 'Sandra dropped the apple' or 'Julius is green' but not both.
There is almost no chance that either 'Sandra dropped the apple' or 'Julius is green' 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.
  0.1::factB.
  0.0::factC.
  %hop1
  0.1::factX:-or(factB,factC).
  0.25::factY:-and(factA,factC).
  0.7::factZ:-xor(factC,factA).

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

  query(conclusion).
  
Either 'Sandra dropped the apple' or 'Julius is green' but not both.