Chances are slight that Bill moved to the office. It is highly likely that Daniel took the milk. It is probably the case that Julius is a swan. Chances are slight that if 'Bill moved to the office' or 'Julius is a swan' or both then Lily is a frog. It is probable that if 'Bill moved to the office' or 'Daniel took the milk' or both then Brian is white. It is unlikely that if 'Daniel took the milk' or 'Julius is a swan' or both then Sandra left the football.
We believe that 'Bill moved to the office and Brian is white'.
It is highly unlikely that 'Bill moved to the office and Brian is white'.
We believe that 'Bill moved to the office 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
  0.1::factA.
  0.9::factB.
  0.7::factC.
  %hop1
  0.1::factX:-or(factA,factC).
  0.7::factY:-or(factA,factB).
  0.2::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Bill moved to the office and Brian is white'.