It is certain that Brian is a frog. It is unlikely that Lily is a rhino. We believe that Sumit is bored. It is impossible that if either 'Sumit is bored' or 'Brian is a frog' but not both then Bill went to the kitchen. There is little chance that if either 'Brian is a frog' or 'Lily is a rhino' but not both then Bernhard is white. We believe that if either 'Lily is a rhino' or 'Sumit is bored' but not both then Sandra got the milk.
It is certain that 'Bernhard is white and Brian is a frog'.
It is improbable that 'Bernhard is white and Brian is a frog'.
It is certain that 'Bernhard is white and Brian is a frog'.

  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
  1.0::factA.
  0.2::factB.
  0.75::factC.
  %hop1
  0.0::factX:-xor(factC,factA).
  0.1::factY:-xor(factA,factB).
  0.75::factZ:-xor(factB,factC).

  %hop2
  conclusion:-and(factY,factA).

  query(conclusion).
  
'Bernhard is white and Brian is a frog'.