It is highly likely that Mary left the football. It is probably the case that Julius is a swan. It is highly unlikely that Winona is a sheep. Chances are slight that if 'Mary left the football and Winona is a sheep' then Bernhard is yellow. It is probably the case that if 'Mary left the football' or 'Julius is a swan' or both then Lily is a lion. There is almost no chance that if 'Julius is a swan' or 'Winona is a sheep' or both then John went to the office.
It is probably the case that 'Winona is a sheep and John went to the office'.
It is impossible that 'Winona is a sheep and John went to the office'.
It is probably the case that 'Winona is a sheep and John went to the office'.

  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
  0.9::factA.
  0.7::factB.
  0.05::factC.
  %hop1
  0.1::factX:-and(factA,factC).
  0.7::factY:-or(factA,factB).
  0.02::factZ:-or(factB,factC).

  %hop2
  conclusion:-and(factC,factZ).

  query(conclusion).
  
'Winona is a sheep and John went to the office'.