It is probably the case that Greg is a frog. It is probably the case that Brian is a rhino. We believe that Jessica is a sheep. It is improbable that if either 'Greg is a frog' or 'Jessica is a sheep' but not both then John took the apple. Chances are slight that if 'Greg is a frog' or 'Jessica is a sheep' or both then Mary went to the bedroom. It is highly likely that if either 'Brian is a rhino' or 'Jessica is a sheep' but not both then Jason is tired.
It is probably not the case that either 'Jessica is a sheep' or 'Jason is tired' but not both.
It is probable that either 'Jessica is a sheep' or 'Jason is tired' but not both.
It is probably not the case that either 'Jessica is a sheep' or 'Jason is tired' 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.
  0.75::factC.
  %hop1
  0.1::factX:-xor(factA,factC).
  0.1::factY:-or(factA,factC).
  0.9::factZ:-xor(factB,factC).

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

  query(conclusion).
  
Either 'Jessica is a sheep' or 'Jason is tired' but not both.