It is probable that Lily is a rhino. It is likely that Brian is gray. It is improbable that Sumit is bored. We believe that if 'Lily is a rhino' or 'Sumit is bored' or both then Mary is in the hallway. There is little chance that if 'Lily is a rhino' or 'Brian is gray' or both then Greg is green. There is almost no chance that if 'Sumit is bored and Brian is gray' then John took the football.
Chances are slight that 'Brian is gray' or 'Greg is green' or both.
It is likely that 'Brian is gray' or 'Greg is green' or both.
Chances are slight that 'Brian is gray' or 'Greg is green' 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.
  0.1::factC.
  %hop1
  0.75::factX:-or(factA,factC).
  0.1::factY:-or(factA,factB).
  0.02::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Brian is gray' or 'Greg is green' or both.