It is almost certain that Mary went to the office. It is probably not the case that Greg is a swan. There is little chance that Bernhard is gray. There is little chance that if either 'Greg is a swan' or 'Mary went to the office' but not both then Jason is tired. We believe that if 'Greg is a swan' or 'Bernhard is gray' or both then Lily is yellow. It is highly likely that if 'Greg is a swan' or 'Bernhard is gray' or both then Brian is a lion.
It is impossible that 'Jason is tired and Greg is a swan'.
It is impossible that 'Jason is tired and Greg is a swan'.
It is likely that 'Jason is tired and Greg is a swan'.

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

  %hop2
  conclusion:-and(factX,factB).

  query(conclusion).
  
'Jason is tired and Greg is a swan'.