There is almost no chance that Mary went to the hallway. It is unlikely that Julius is a rhino. It is highly likely that Jeff moved to the office. It is highly unlikely that if 'Mary went to the hallway' or 'Jeff moved to the office' or both then Greg is white. There is a very good chance that if either 'Julius is a rhino' or 'Jeff moved to the office' but not both then Jessica is a mouse. It is highly unlikely that if either 'Jeff moved to the office' or 'Julius is a rhino' but not both then Bernhard is green.
There is almost no chance that 'Jessica is a mouse' or 'Greg is white' or both.
There is a better than even chance that 'Jessica is a mouse' or 'Greg is white' or both.
There is almost no chance that 'Jessica is a mouse' or 'Greg is white' 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
  0.02::factA.
  0.2::factB.
  0.9::factC.
  %hop1
  0.05::factX:-or(factA,factC).
  0.8::factY:-xor(factB,factC).
  0.05::factZ:-xor(factC,factB).

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

  query(conclusion).
  
'Jessica is a mouse' or 'Greg is white' or both.