It is probably not the case that Jessica is a cat. It is probably not the case that Bill went to the garden. It is unlikely that Antoine is thirsty. It is unlikely that if 'Jessica is a cat and Bill went to the garden' then Daniel got the milk. There is a better than even chance that if either 'Jessica is a cat' or 'Bill went to the garden' but not both then Bernhard is a swan. There is almost no chance that if either 'Jessica is a cat' or 'Bill went to the garden' but not both then Brian is a frog.
Chances are about even that 'Bernhard is a swan' or 'Antoine is thirsty' or both.
Chances are about even that 'Bernhard is a swan' or 'Antoine is thirsty' or both.
It is impossible that 'Bernhard is a swan' or 'Antoine is thirsty' 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
  0.25::factA.
  0.25::factB.
  0.2::factC.
  %hop1
  0.2::factX:-and(factA,factB).
  0.6::factY:-xor(factA,factB).
  0.02::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'Bernhard is a swan' or 'Antoine is thirsty' or both.