It is probable that Mary went to the bedroom. We doubt that Lily is white. It is unlikely that John left the football. Chances are slight that if 'Lily is white' or 'John left the football' or both then Winona is a wolf. There is little chance that if either 'Lily is white' or 'Mary went to the bedroom' but not both then Yann is tired. We doubt that if 'John left the football and Lily is white' then Greg is a rhino.
It is highly unlikely that 'Mary went to the bedroom' or 'Yann is tired' or both.
It is probably the case that 'Mary went to the bedroom' or 'Yann is tired' or both.
It is highly unlikely that 'Mary went to the bedroom' or 'Yann is tired' 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
  0.7::factA.
  0.2::factB.
  0.2::factC.
  %hop1
  0.1::factX:-or(factB,factC).
  0.1::factY:-xor(factB,factA).
  0.2::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Mary went to the bedroom' or 'Yann is tired' or both.