There is little chance that Jason is tired. There is a better than even chance that Sandra took the football. We doubt that Jessica is a cat. There is little chance that if either 'Sandra took the football' or 'Jason is tired' but not both then Mary went to the garden. It is probably not the case that if 'Jason is tired and Sandra took the football' then Bernhard is a swan. It is unlikely that if 'Jason is tired and Sandra took the football' then Julius is a lion.
It is unlikely that 'Jessica is a cat' or 'Sandra took the football' or both.
It is probable that 'Jessica is a cat' or 'Sandra took the football' or both.
It is unlikely that 'Jessica is a cat' or 'Sandra took the football' 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
  0.1::factA.
  0.6::factB.
  0.2::factC.
  %hop1
  0.1::factX:-xor(factB,factA).
  0.25::factY:-and(factA,factB).
  0.2::factZ:-and(factA,factB).

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

  query(conclusion).
  
'Jessica is a cat' or 'Sandra took the football' or both.