It is highly unlikely that Greg is a rhino. It is highly unlikely that Jason is tired. It is probably the case that Brian is a swan. There is almost no chance that if 'Greg is a rhino and Brian is a swan' then Bernhard is yellow. There is almost no chance that if 'Jason is tired' or 'Brian is a swan' or both then Lily is a rhino. It is impossible that if 'Brian is a swan and Greg is a rhino' then John picked up the apple.
It is likely that 'Bernhard is yellow and Brian is a swan'.
It is impossible that 'Bernhard is yellow and Brian is a swan'.
It is likely that 'Bernhard is yellow and Brian 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
  0.05::factA.
  0.05::factB.
  0.7::factC.
  %hop1
  0.02::factX:-and(factA,factC).
  0.02::factY:-or(factB,factC).
  0.0::factZ:-and(factC,factA).

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

  query(conclusion).
  
'Bernhard is yellow and Brian is a swan'.