We believe that John went to the garden. It is highly unlikely that Sandra dropped the milk. There is a better than even chance that Lily is a rhino. We doubt that if 'Sandra dropped the milk' or 'John went to the garden' or both then Bernhard is green. There is little chance that if 'Lily is a rhino and John went to the garden' then Brian is white. Chances are about even that if 'Lily is a rhino and John went to the garden' then Mary is in the school.
There is a better than even chance that 'Brian is white and John went to the garden'.
It is highly unlikely that 'Brian is white and John went to the garden'.
There is a better than even chance that 'Brian is white and John 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
  0.75::factA.
  0.05::factB.
  0.6::factC.
  %hop1
  0.2::factX:-or(factB,factA).
  0.1::factY:-and(factC,factA).
  0.5::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Brian is white and John went to the garden'.