It is probably the case that Brian is a lion. There is almost no chance that Julius is a frog. It is probably the case that Jessica is a cat. There is a very good chance that if 'Julius is a frog and Brian is a lion' then Sumit is thirsty. It is probably not the case that if either 'Julius is a frog' or 'Brian is a lion' but not both then Fred put down the apple. It is highly likely that if 'Jessica is a cat' or 'Julius is a frog' or both then Mary took the milk.
Chances are about even that 'Mary took the milk and Brian is a lion'.
Chances are about even that 'Mary took the milk and Brian is a lion'.
It is almost certain that 'Mary took the milk and Brian 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
  0.7::factA.
  0.02::factB.
  0.7::factC.
  %hop1
  0.8::factX:-and(factB,factA).
  0.25::factY:-xor(factB,factA).
  0.9::factZ:-or(factC,factB).

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

  query(conclusion).
  
'Mary took the milk and Brian is a lion'.