There is little chance that Jason is tired. It is probable that Lily is a swan. It is probably the case that Bernhard is a frog. It is highly unlikely that if 'Lily is a swan and Jason is tired' then Sandra got the milk. We doubt that if 'Jason is tired and Lily is a swan' then Daniel left the apple. It is improbable that if 'Bernhard is a frog' or 'Jason is tired' or both then John went to the kitchen.
It is probable that 'Lily is a swan and Jason is tired'.
It is highly unlikely that 'Lily is a swan and Jason is tired'.
It is probable that 'Lily is a swan and Jason is tired'.

  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
  0.1::factA.
  0.7::factB.
  0.7::factC.
  %hop1
  0.05::factX:-and(factB,factA).
  0.2::factY:-and(factA,factB).
  0.1::factZ:-or(factC,factA).

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

  query(conclusion).
  
'Lily is a swan and Jason is tired'.