It is likely that Mary picked up the milk. Chances are slight that Bernhard is yellow. It is probably the case that Brian is white. We believe that if 'Bernhard is yellow and Mary picked up the milk' then Sandra got the football. It is almost certain that if either 'Mary picked up the milk' or 'Brian is white' but not both then Julius is a lion. There is a very good chance that if 'Mary picked up the milk and Brian is white' then Jeff went to the garden.
We believe that 'Bernhard is yellow and Jeff went to the garden'.
It is highly unlikely that 'Bernhard is yellow and Jeff went to the garden'.
We believe that 'Bernhard is yellow and Jeff went to the garden'.

  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.
  0.1::factB.
  0.7::factC.
  %hop1
  0.75::factX:-and(factB,factA).
  0.95::factY:-xor(factA,factC).
  0.8::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Bernhard is yellow and Jeff went to the garden'.