It is probable that Sumit is thirsty. We doubt that John discarded the apple. Chances are slight that Greg is a lion. Chances are slight that if either 'Sumit is thirsty' or 'Greg is a lion' but not both then Mary left the football. It is certain that if 'Sumit is thirsty and Greg is a lion' then Bernhard is a swan. It is probable that if either 'Greg is a lion' or 'Sumit is thirsty' but not both then Fred went to the office.
Chances are slight that 'Sumit is thirsty and John discarded the apple'.
Chances are slight that 'Sumit is thirsty and John discarded the apple'.
It is almost certain that 'Sumit is thirsty 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
  0.7::factA.
  0.2::factB.
  0.1::factC.
  %hop1
  0.1::factX:-xor(factA,factC).
  1.0::factY:-and(factA,factC).
  0.7::factZ:-xor(factC,factA).

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

  query(conclusion).
  
'Sumit is thirsty and John discarded the apple'.