It is likely that Jeff moved to the garden. Chances are about even that John got the apple. There is a better than even chance that Jessica is a mouse. It is likely that if 'John got the apple and Jessica is a mouse' then Greg is yellow. It is highly unlikely that if 'Jeff moved to the garden and Jessica is a mouse' then Brian is a rhino. It is certain that if 'Jessica is a mouse' or 'John got the apple' or both then Julius is white.
Chances are about even that either 'Greg is yellow' or 'Jessica is a mouse' but not both.
Chances are about even that either 'Greg is yellow' or 'Jessica is a mouse' but not both.
It is highly unlikely that either 'Greg is yellow' or 'Jessica 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
  0.7::factA.
  0.5::factB.
  0.6::factC.
  %hop1
  0.7::factX:-and(factB,factC).
  0.05::factY:-and(factA,factC).
  1.0::factZ:-or(factC,factB).

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

  query(conclusion).
  
Either 'Greg is yellow' or 'Jessica is a mouse' but not both.