We believe that Julius is a rhino. There is a very good chance that Lily is a swan. It is probably not the case that John left the apple. It is highly likely that if 'John left the apple' or 'Lily is a swan' or both then Mary went to the bedroom. It is likely that if either 'Julius is a rhino' or 'Lily is a swan' but not both then Winona is a mouse. It is highly likely that if either 'Julius is a rhino' or 'Lily is a swan' but not both then Sandra took the football.
It is highly likely that 'Lily is a swan' or 'Winona is a mouse' or both.
It is highly likely that 'Lily is a swan' or 'Winona is a mouse' or both.
It is unlikely that 'Lily is a swan' or 'Winona 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
  0.75::factA.
  0.8::factB.
  0.25::factC.
  %hop1
  0.9::factX:-or(factC,factB).
  0.7::factY:-xor(factA,factB).
  0.9::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Lily is a swan' or 'Winona is a mouse' or both.