There is little chance that Greg is yellow. It is almost certain that Mary moved to the office. Chances are about even that Lily is a swan. It is highly likely that if 'Mary moved to the office and Greg is yellow' then Jeff dropped the apple. It is certain that if 'Lily is a swan and Mary moved to the office' then Brian is a rhino. Chances are about even that if 'Greg is yellow' or 'Mary moved to the office' or both then Bernhard is green.
It is unlikely that 'Bernhard is green' or 'Mary moved to the office' or both.
It is almost certain that 'Bernhard is green' or 'Mary moved to the office' or both.
It is unlikely that 'Bernhard 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
  0.1::factA.
  0.95::factB.
  0.5::factC.
  %hop1
  0.9::factX:-and(factB,factA).
  1.0::factY:-and(factC,factB).
  0.5::factZ:-or(factA,factB).

  %hop2
  conclusion:-or(factZ,factB).

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