We believe that Mary got the apple. There is almost no chance that Brian is a rhino. It is impossible that Bernhard is green. It is impossible that if 'Brian is a rhino' or 'Bernhard is green' or both then John discarded the milk. It is unlikely that if 'Mary got the apple' or 'Bernhard is green' or both then Julius is a swan. We believe that if 'Brian is a rhino' or 'Bernhard is green' or both then Sandra left the football.
It is impossible that 'Bernhard is green and Mary got the apple'.
It is impossible that 'Bernhard is green and Mary got the apple'.
We believe that 'Bernhard is green and Mary got the apple'.

  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.
  0.02::factB.
  0.0::factC.
  %hop1
  0.0::factX:-or(factB,factC).
  0.2::factY:-or(factA,factC).
  0.75::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Bernhard is green and Mary got the apple'.