There is a better than even chance that Greg is a frog. We believe that Emily is a sheep. It is probably the case that Brian is a lion. It is likely that if either 'Greg is a frog' or 'Emily is a sheep' but not both then Bernhard is green. We doubt that if 'Emily is a sheep' or 'Greg is a frog' or both then Fred is in the school. There is a very good chance that if 'Brian is a lion and Greg is a frog' then Winona is a mouse.
It is almost certain that either 'Emily is a sheep' or 'Greg is a frog' but not both.
Chances are about even that either 'Emily is a sheep' or 'Greg is a frog' but not both.
It is almost certain that either 'Emily is a sheep' or 'Greg is a frog' 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
  0.6::factA.
  0.75::factB.
  0.7::factC.
  %hop1
  0.7::factX:-xor(factA,factB).
  0.2::factY:-or(factB,factA).
  0.8::factZ:-and(factC,factA).

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

  query(conclusion).
  
Either 'Emily is a sheep' or 'Greg is a frog' but not both.