Chances are about even that Fred moved to the office. There is a very good chance that Brian is a lion. Chances are slight that Julius is a rhino. There is almost no chance that if 'Julius is a rhino' or 'Fred moved to the office' or both then Mary put down the milk. It is unlikely that if 'Brian is a lion and Fred moved to the office' then Bernhard is a frog. It is improbable that if 'Brian is a lion and Julius is a rhino' then John went to the kitchen.
Chances are slight that 'Brian is a lion and Bernhard is a frog'.
Chances are slight that 'Brian is a lion and Bernhard is a frog'.
It is probably the case that 'Brian is a lion and Bernhard is a frog'.

  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
  0.5::factA.
  0.8::factB.
  0.1::factC.
  %hop1
  0.02::factX:-or(factC,factA).
  0.2::factY:-and(factB,factA).
  0.1::factZ:-and(factB,factC).

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

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