It is probable that Bernhard is a swan. There is a better than even chance that Fred put down the apple. It is highly likely that Brian is green. We believe that if 'Brian is green and Fred put down the apple' then Greg is a rhino. It is highly likely that if 'Brian is green and Fred put down the apple' then Mary went to the bedroom. We doubt that if 'Fred put down the apple and Bernhard is a swan' then John discarded the milk.
It is likely that 'John discarded the milk' or 'Bernhard is a swan' or both.
It is likely that 'John discarded the milk' or 'Bernhard is a swan' or both.
We doubt that 'John discarded the milk' or 'Bernhard is a swan' 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
  0.7::factA.
  0.6::factB.
  0.9::factC.
  %hop1
  0.75::factX:-and(factC,factB).
  0.9::factY:-and(factC,factB).
  0.2::factZ:-and(factB,factA).

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

  query(conclusion).
  
'John discarded the milk' or 'Bernhard is a swan' or both.