It is impossible that Mary dropped the milk. It is likely that Bernhard is yellow. There is a better than even chance that Brian is white. It is likely that if 'Bernhard is yellow' or 'Brian is white' or both then Julius is a swan. It is highly unlikely that if 'Mary dropped the milk and Bernhard is yellow' then Sumit is bored. It is certain that if 'Bernhard is yellow and Mary dropped the milk' then John went to the garden.
There is a better than even chance that 'Mary dropped the milk and Sumit is bored'.
It is impossible that 'Mary dropped the milk and Sumit is bored'.
There is a better than even chance that 'Mary dropped the milk and Sumit is bored'.

  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
  0.0::factA.
  0.7::factB.
  0.6::factC.
  %hop1
  0.7::factX:-or(factB,factC).
  0.05::factY:-and(factA,factB).
  1.0::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Mary dropped the milk and Sumit is bored'.