We believe that Mary put down the apple. It is highly unlikely that Jason is tired. There is little chance that Bernhard is a rhino. We doubt that if 'Jason is tired and Bernhard is a rhino' then Brian is a frog. It is certain that if either 'Jason is tired' or 'Mary put down the apple' but not both then Sandra grabbed the milk. There is a very good chance that if 'Bernhard is a rhino and Jason is tired' then Winona is a wolf.
It is certain that 'Brian is a frog and Bernhard is a rhino'.
It is impossible that 'Brian is a frog and Bernhard is a rhino'.
It is certain that 'Brian is a frog and Bernhard is a rhino'.

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

  %hop2
  conclusion:-and(factX,factC).

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