It is probable that John took the football. It is unlikely that Mary picked up the apple. It is improbable that Julius is a rhino. It is probably the case that if 'John took the football and Julius is a rhino' then Jessica is a cat. It is almost certain that if either 'Julius is a rhino' or 'Mary picked up the apple' but not both then Winona is a mouse. There is a better than even chance that if 'Julius is a rhino' or 'John took the football' or both then Bernhard is a frog.
It is certain that either 'Mary picked up the apple' or 'Jessica is a cat' but not both.
It is probably not the case that either 'Mary picked up the apple' or 'Jessica is a cat' but not both.
It is certain that either 'Mary picked up the apple' or 'Jessica is a cat' 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.
  0.2::factB.
  0.1::factC.
  %hop1
  0.7::factX:-and(factA,factC).
  0.95::factY:-xor(factC,factB).
  0.6::factZ:-or(factC,factA).

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

  query(conclusion).
  
Either 'Mary picked up the apple' or 'Jessica is a cat' but not both.