There is almost no chance that Greg is a frog. It is probably the case that Winona is a sheep. Chances are about even that Lily is a lion. It is probably not the case that if 'Winona is a sheep and Lily is a lion' then John got the milk. It is highly unlikely that if either 'Winona is a sheep' or 'Lily is a lion' but not both then Sandra grabbed the apple. It is almost certain that if 'Winona is a sheep and Greg is a frog' then Mary went to the garden.
It is certain that 'Mary went to the garden and Lily is a lion'.
It is impossible that 'Mary went to the garden and Lily is a lion'.
It is certain that 'Mary went to the garden and Lily is a lion'.

  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
  0.02::factA.
  0.7::factB.
  0.5::factC.
  %hop1
  0.25::factX:-and(factB,factC).
  0.05::factY:-xor(factB,factC).
  0.95::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Mary went to the garden and Lily is a lion'.