It is probably not the case that Sumit is tired. It is likely that Brian is white. It is highly unlikely that Daniel dropped the apple. Chances are about even that if 'Sumit is tired' or 'Brian is white' or both then Emily is a cat. It is improbable that if either 'Brian is white' or 'Sumit is tired' but not both then Lily is yellow. Chances are about even that if 'Sumit is tired' or 'Brian is white' or both then John went to the bedroom.
There is a very good chance that 'Brian is white' or 'Sumit is tired' or both.
There is a very good chance that 'Brian is white' or 'Sumit is tired' or both.
There is little chance that 'Brian is white' or 'Sumit is tired' 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
  0.25::factA.
  0.7::factB.
  0.05::factC.
  %hop1
  0.5::factX:-or(factA,factB).
  0.1::factY:-xor(factB,factA).
  0.5::factZ:-or(factA,factB).

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

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