It is improbable that Lily is white. We doubt that Mary went to the bedroom. It is probably not the case that Bill moved to the office. It is improbable that if either 'Mary went to the bedroom' or 'Lily is white' but not both then Jeff left the apple. There is almost no chance that if 'Mary went to the bedroom' or 'Lily is white' or both then Greg is a lion. There is a very good chance that if 'Lily is white and Mary went to the bedroom' then Jessica is a cat.
It is highly unlikely that 'Jessica is a cat' or 'Jeff left the apple' or both.
It is highly unlikely that 'Jessica is a cat' or 'Jeff left the apple' or both.
Chances are about even that 'Jessica is a cat' or 'Jeff left the apple' 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.
  0.2::factB.
  0.25::factC.
  %hop1
  0.1::factX:-xor(factB,factA).
  0.02::factY:-or(factB,factA).
  0.8::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Jessica is a cat' or 'Jeff left the apple' or both.