There is a very good chance that Brian is green. It is probably not the case that Bernhard is yellow. It is improbable that Greg is gray. It is almost certain that if 'Bernhard is yellow and Greg is gray' then Julius is white. There is a better than even chance that if 'Greg is gray and Brian is green' then Mary moved to the office. It is probable that if 'Greg is gray and Bernhard is yellow' then John discarded the apple.
There is a very good chance that 'Brian is green' or 'Mary moved to the office' or both.
There is a very good chance that 'Brian is green' or 'Mary moved to the office' or both.
It is impossible that 'Brian is green' or 'Mary moved to the office' 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
  0.8::factA.
  0.25::factB.
  0.1::factC.
  %hop1
  0.95::factX:-and(factB,factC).
  0.6::factY:-and(factC,factA).
  0.7::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Brian is green' or 'Mary moved to the office' or both.