It is improbable that Jessica is a cat. It is highly likely that Bernhard is yellow. It is highly unlikely that Lily is white. There is almost no chance that if 'Jessica is a cat' or 'Lily is white' or both then Antoine is thirsty. It is improbable that if either 'Jessica is a cat' or 'Lily is white' but not both then Mary went to the office. We believe that if either 'Bernhard is yellow' or 'Jessica is a cat' but not both then John discarded the apple.
It is impossible that 'John discarded the apple and Jessica is a cat'.
It is impossible that 'John discarded the apple and Jessica is a cat'.
It is certain that 'John discarded the apple and Jessica is a cat'.

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

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

  query(conclusion).
  
'John discarded the apple and Jessica is a cat'.