It is impossible that Julius is gray. There is little chance that John put down the apple. Chances are slight that Emily is a sheep. There is a very good chance that if either 'John put down the apple' or 'Julius is gray' but not both then Sumit is tired. We believe that if 'Emily is a sheep' or 'Julius is gray' or both then Jeff left the apple. It is unlikely that if 'Emily is a sheep' or 'John put down the apple' or both then Brian is a rhino.
There is a better than even chance that 'Sumit is tired' or 'Brian is a rhino' or both.
It is improbable that 'Sumit is tired' or 'Brian is a rhino' or both.
There is a better than even chance that 'Sumit is tired' or 'Brian is a rhino' 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
  0.0::factA.
  0.1::factB.
  0.1::factC.
  %hop1
  0.8::factX:-xor(factB,factA).
  0.75::factY:-or(factC,factA).
  0.2::factZ:-or(factC,factB).

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

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