There is little chance that Jason is tired. It is unlikely that Lily is a swan. It is highly likely that Brian is a frog. It is probably the case that if 'Jason is tired and Lily is a swan' then Bernhard is white. Chances are about even that if 'Brian is a frog and Lily is a swan' then Mary got the football. Chances are about even that if 'Jason is tired and Lily is a swan' then John went to the garden.
There is almost no chance that 'Bernhard is white and Brian is a frog'.
There is almost no chance that 'Bernhard is white and Brian is a frog'.
It is probable 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
  0.1::factA.
  0.2::factB.
  0.9::factC.
  %hop1
  0.7::factX:-and(factA,factB).
  0.5::factY:-and(factC,factB).
  0.5::factZ:-and(factA,factB).

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

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