It is improbable that John discarded the apple. There is a better than even chance that Julius is a swan. It is almost certain that Brian is yellow. It is likely that if either 'John discarded the apple' or 'Julius is a swan' but not both then Mary left the football. Chances are slight that if 'John discarded the apple' or 'Brian is yellow' or both then Lily is a frog. It is certain that if 'Julius is a swan and John discarded the apple' then Sumit is thirsty.
There is almost no chance that 'Mary left the football and John discarded the apple'.
There is almost no chance that 'Mary left the football and John discarded the apple'.
It is probable that 'Mary left the football and John discarded the apple'.

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

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

  query(conclusion).
  
'Mary left the football and John discarded the apple'.