It is probably the case that John took the apple. It is unlikely that Julius is a lion. It is likely that Lily is white. We doubt that if 'Lily is white and Julius is a lion' then Yann is thirsty. It is highly likely that if 'Julius is a lion and Lily is white' then Brian is a frog. Chances are about even that if 'Lily is white and Julius is a lion' then Mary moved to the office.
There is little chance that 'Brian is a frog and Julius is a lion'.
There is little chance that 'Brian is a frog and Julius is a lion'.
It is probable that 'Brian is a frog and Julius 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.
  0.2::factB.
  0.7::factC.
  %hop1
  0.2::factX:-and(factC,factB).
  0.9::factY:-and(factB,factC).
  0.5::factZ:-and(factC,factB).

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

  query(conclusion).
  
'Brian is a frog and Julius is a lion'.