It is probably the case that Bernhard is green. There is almost no chance that Gertrude is a mouse. It is certain that Sandra left the milk. There is a better than even chance that if either 'Gertrude is a mouse' or 'Bernhard is green' but not both then Julius is gray. There is a very good chance that if 'Gertrude is a mouse' or 'Sandra left the milk' or both then Jeff moved to the garden. There is little chance that if 'Gertrude is a mouse and Sandra left the milk' then Brian is white.
It is impossible that 'Jeff moved to the garden' or 'Julius is gray' or both.
It is highly likely that 'Jeff moved to the garden' or 'Julius is gray' or both.
It is impossible that 'Jeff moved to the garden' or 'Julius is gray' or 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.
  0.02::factB.
  1.0::factC.
  %hop1
  0.6::factX:-xor(factB,factA).
  0.8::factY:-or(factB,factC).
  0.1::factZ:-and(factB,factC).

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

  query(conclusion).
  
'Jeff moved to the garden' or 'Julius is gray' or both.