It is highly unlikely that Brian is a frog. It is highly unlikely that Greg is a swan. It is unlikely that Mary left the football. There is a very good chance that if 'Brian is a frog' or 'Greg is a swan' or both then Bernhard is gray. It is unlikely that if 'Mary left the football and Greg is a swan' then Yann is thirsty. It is almost certain that if 'Greg is a swan' or 'Mary left the football' or both then Winona is a mouse.
It is likely that 'Mary left the football and Winona is a mouse'.
It is unlikely that 'Mary left the football and Winona is a mouse'.
It is likely that 'Mary left the football and Winona is a mouse'.

  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
  0.05::factA.
  0.05::factB.
  0.2::factC.
  %hop1
  0.8::factX:-or(factA,factB).
  0.2::factY:-and(factC,factB).
  0.95::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Mary left the football and Winona is a mouse'.