It is probable that Jason is tired. We doubt that Jessica is a cat. It is almost certain that Sandra dropped the milk. It is highly unlikely that if 'Jessica is a cat' or 'Jason is tired' or both then Julius is white. It is improbable that if 'Sandra dropped the milk' or 'Jason is tired' or both then Emily is a wolf. There is almost no chance that if either 'Jessica is a cat' or 'Jason is tired' but not both then Bernhard is a swan.
It is improbable that 'Jason is tired' or 'Jessica is a cat' or both.
We believe that 'Jason is tired' or 'Jessica is a cat' or both.
It is improbable that 'Jason is tired' or 'Jessica is a cat' 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.
  0.2::factB.
  0.95::factC.
  %hop1
  0.05::factX:-or(factB,factA).
  0.1::factY:-or(factC,factA).
  0.02::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Jason is tired' or 'Jessica is a cat' or both.