It is almost certain that Gertrude is a cat. It is probably the case that Lily is a rhino. It is certain that Mary left the football. We doubt that if either 'Mary left the football' or 'Gertrude is a cat' but not both then Bernhard is green. It is almost certain that if either 'Gertrude is a cat' or 'Mary left the football' but not both then John got the football. Chances are about even that if 'Lily is a rhino and Gertrude is a cat' then Bill moved to the office.
It is impossible that 'Bernhard is green and Gertrude is a cat'.
It is impossible that 'Bernhard is green and Gertrude is a cat'.
There is a better than even chance that 'Bernhard is green and Gertrude is a cat'.

  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
  0.95::factA.
  0.7::factB.
  1.0::factC.
  %hop1
  0.2::factX:-xor(factC,factA).
  0.95::factY:-xor(factA,factC).
  0.5::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Bernhard is green and Gertrude is a cat'.