It is probable that Bernhard is green. It is improbable that Emily is a mouse. It is probable that Julius is white. It is certain that if 'Emily is a mouse' or 'Julius is white' or both then Lily is a swan. It is certain that if 'Julius is white' or 'Emily is a mouse' or both then Mary went to the office. It is highly unlikely that if 'Bernhard is green' or 'Julius is white' or both then Brian is a swan.
Chances are slight that 'Brian is a swan' or 'Emily is a mouse' or both.
Chances are slight that 'Brian is a swan' or 'Emily is a mouse' or both.
We believe that 'Brian is a swan' or 'Emily is a mouse' or both.

  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
  1.0::factX:-or(factB,factC).
  1.0::factY:-or(factC,factB).
  0.05::factZ:-or(factA,factC).

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

  query(conclusion).
  
'Brian is a swan' or 'Emily is a mouse' or both.