There is a better than even chance that Brian is white. Chances are about even that Fred dropped the apple. It is almost certain that Gertrude is a sheep. It is probably not the case that if 'Fred dropped the apple' or 'Gertrude is a sheep' or both then Daniel left the football. It is impossible that if 'Brian is white' or 'Fred dropped the apple' or both then Greg is a frog. There is a very good chance that if 'Fred dropped the apple' or 'Brian is white' or both then Lily is a rhino.
It is probable that 'Daniel left the football and Brian is white'.
Chances are slight that 'Daniel left the football and Brian is white'.
It is probable that 'Daniel left the football and Brian is white'.

  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
  0.6::factA.
  0.5::factB.
  0.95::factC.
  %hop1
  0.25::factX:-or(factB,factC).
  0.0::factY:-or(factA,factB).
  0.8::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Daniel left the football and Brian is white'.