It is likely that John grabbed the apple. It is likely that Brian is white. It is probably the case that Sandra left the milk. We doubt that if 'John grabbed the apple' or 'Sandra left the milk' or both then Sumit is bored. We believe that if 'John grabbed the apple' or 'Brian is white' or both then Bernhard is yellow. It is highly likely that if 'Brian is white and John grabbed the apple' then Lily is a swan.
It is improbable that 'Sumit is bored' or 'Brian is white' or both.
We believe that 'Sumit is bored' or 'Brian is white' or both.
It is improbable that 'Sumit is bored' or 'Brian is white' 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.
  0.7::factB.
  0.7::factC.
  %hop1
  0.2::factX:-or(factA,factC).
  0.75::factY:-or(factA,factB).
  0.9::factZ:-and(factB,factA).

  %hop2
  conclusion:-or(factX,factB).

  query(conclusion).
  
'Sumit is bored' or 'Brian is white' or both.