It is highly unlikely that Julius is a rhino. Chances are slight that Bernhard is a frog. It is certain that Brian is green. It is highly unlikely that if 'Brian is green and Bernhard is a frog' then Gertrude is a mouse. It is probably the case that if 'Bernhard is a frog' or 'Julius is a rhino' or both then Emily is a sheep. It is impossible that if 'Brian is green' or 'Bernhard is a frog' or both then Mary put down the apple.
It is probably the case that either 'Emily is a sheep' or 'Gertrude is a mouse' but not both.
It is improbable that either 'Emily is a sheep' or 'Gertrude is a mouse' but not both.
It is probably the case that either 'Emily is a sheep' or 'Gertrude is a mouse' 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
  0.05::factA.
  0.1::factB.
  1.0::factC.
  %hop1
  0.05::factX:-and(factC,factB).
  0.7::factY:-or(factB,factA).
  0.0::factZ:-or(factC,factB).

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

  query(conclusion).
  
Either 'Emily is a sheep' or 'Gertrude is a mouse' but not both.