Chances are about even that Lily is a rhino. We believe that Winona is a mouse. It is highly unlikely that John went to the hallway. It is likely that if 'Lily is a rhino' or 'Winona is a mouse' or both then Jeff moved to the office. Chances are about even that if 'John went to the hallway' or 'Winona is a mouse' or both then Greg is green. It is highly unlikely that if 'Winona is a mouse and John went to the hallway' then Julius is a swan.
There is little chance that 'Jeff moved to the office' or 'Julius is a swan' or both.
There is a better than even chance that 'Jeff moved to the office' or 'Julius is a swan' or both.
There is little chance that 'Jeff moved to the office' or 'Julius is a swan' 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
  0.5::factA.
  0.75::factB.
  0.05::factC.
  %hop1
  0.7::factX:-or(factA,factB).
  0.5::factY:-or(factC,factB).
  0.05::factZ:-and(factB,factC).

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

  query(conclusion).
  
'Jeff moved to the office' or 'Julius is a swan' or both.