It is probably not the case that John went to the hallway. It is almost certain that Mary moved to the office. Chances are slight that Bernhard is a frog. We doubt that if either 'Bernhard is a frog' or 'Mary moved to the office' but not both then Julius is white. We believe that if 'John went to the hallway and Bernhard is a frog' then Brian is a lion. It is probable that if 'Mary moved to the office and John went to the hallway' then Greg is a swan.
It is probable that 'Brian is a lion' or 'John went to the hallway' or both.
It is probably not the case that 'Brian is a lion' or 'John went to the hallway' or both.
It is probable that 'Brian is a lion' or 'John went to the hallway' 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
  0.25::factA.
  0.95::factB.
  0.1::factC.
  %hop1
  0.2::factX:-xor(factC,factB).
  0.75::factY:-and(factA,factC).
  0.7::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Brian is a lion' or 'John went to the hallway' or both.