It is improbable that Sandra left the milk. It is highly likely that John took the milk. It is probable that Mary went to the office. It is highly unlikely that if 'Mary went to the office' or 'John took the milk' or both then Julius is a frog. Chances are about even that if 'Mary went to the office' or 'Sandra left the milk' or both then Lily is green. It is impossible that if 'Sandra left the milk' or 'Mary went to the office' or both then Bernhard is a rhino.
It is highly likely that 'Sandra left the milk and Bernhard is a rhino'.
It is impossible that 'Sandra left the milk and Bernhard is a rhino'.
It is highly likely that 'Sandra left the milk and Bernhard is a rhino'.

  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
  0.1::factA.
  0.9::factB.
  0.7::factC.
  %hop1
  0.05::factX:-or(factC,factB).
  0.5::factY:-or(factC,factA).
  0.0::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Sandra left the milk and Bernhard is a rhino'.