It is likely that Julius is a frog. There is a very good chance that Lily is green. It is impossible that John left the football. It is highly unlikely that if either 'Lily is green' or 'John left the football' but not both then Bernhard is yellow. It is probably not the case that if either 'John left the football' or 'Lily is green' but not both then Daniel dropped the apple. It is probable that if 'John left the football and Lily is green' then Fred went to the garden.
It is impossible that 'Fred went to the garden and Julius is a frog'.
It is impossible that 'Fred went to the garden and Julius is a frog'.
We believe that 'Fred went to the garden and Julius 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
  0.7::factA.
  0.8::factB.
  0.0::factC.
  %hop1
  0.05::factX:-xor(factB,factC).
  0.25::factY:-xor(factC,factB).
  0.7::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Fred went to the garden and Julius is a frog'.