It is almost certain that Greg is a swan. It is probably the case that Antoine is bored. There is little chance that Brian is a frog. There is almost no chance that if either 'Greg is a swan' or 'Antoine is bored' but not both then Mary went to the hallway. There is a better than even chance that if either 'Antoine is bored' or 'Greg is a swan' but not both then John took the apple. We believe that if 'Antoine is bored' or 'Greg is a swan' or both then Sumit is hungry.
We believe that 'Antoine is bored' or 'Brian is a frog' or both.
We believe that 'Antoine is bored' or 'Brian is a frog' or both.
It is impossible that 'Antoine is bored' or 'Brian is a frog' 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
  0.95::factA.
  0.7::factB.
  0.1::factC.
  %hop1
  0.02::factX:-xor(factA,factB).
  0.6::factY:-xor(factB,factA).
  0.75::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Antoine is bored' or 'Brian is a frog' or both.