It is impossible that Bernhard is a swan. It is highly unlikely that Brian is a frog. There is a better than even chance that Lily is green. It is improbable that if 'Brian is a frog and Bernhard is a swan' then Greg is white. It is highly unlikely that if 'Lily is green and Brian is a frog' then Mary went to the hallway. There is a better than even chance that if either 'Bernhard is a swan' or 'Lily is green' but not both then Jessica is a cat.
There is almost no chance that 'Jessica is a cat' or 'Lily is green' or both.
There is a better than even chance that 'Jessica is a cat' or 'Lily is green' or both.
There is almost no chance that 'Jessica is a cat' or 'Lily is green' 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
  0.0::factA.
  0.05::factB.
  0.6::factC.
  %hop1
  0.1::factX:-and(factB,factA).
  0.05::factY:-and(factC,factB).
  0.6::factZ:-xor(factA,factC).

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

  query(conclusion).
  
'Jessica is a cat' or 'Lily is green' or both.