We believe that Yann is bored. We believe that Julius is yellow. There is little chance that Mary went to the bedroom. It is improbable that if 'Mary went to the bedroom and Julius is yellow' then Sandra left the milk. It is almost certain that if 'Julius is yellow' or 'Yann is bored' or both then John moved to the office. Chances are slight that if either 'Yann is bored' or 'Julius is yellow' but not both then Bernhard is green.
There is a very good chance that 'John moved to the office and Mary went to the bedroom'.
It is improbable that 'John moved to the office and Mary went to the bedroom'.
There is a very good chance that 'John moved to the office and Mary went to the bedroom'.

  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.
  0.75::factB.
  0.1::factC.
  %hop1
  0.1::factX:-and(factC,factB).
  0.95::factY:-or(factB,factA).
  0.1::factZ:-xor(factA,factB).

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

  query(conclusion).
  
'John moved to the office and Mary went to the bedroom'.