There is a better than even chance that Winona is a sheep. There is a very good chance that Julius is a lion. It is likely that Mary went to the bedroom. It is unlikely that if 'Winona is a sheep' or 'Mary went to the bedroom' or both then Jessica is a mouse. We believe that if 'Winona is a sheep and Mary went to the bedroom' then Greg is gray. Chances are slight that if 'Mary went to the bedroom and Winona is a sheep' then John put down the apple.
It is probably not the case that 'Mary went to the bedroom' or 'Jessica is a mouse' or both.
We believe that 'Mary went to the bedroom' or 'Jessica is a mouse' or both.
It is probably not the case that 'Mary went to the bedroom' or 'Jessica is a mouse' 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
  0.6::factA.
  0.8::factB.
  0.7::factC.
  %hop1
  0.2::factX:-or(factA,factC).
  0.75::factY:-and(factA,factC).
  0.1::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Mary went to the bedroom' or 'Jessica is a mouse' or both.