There is little chance that Bernhard is a frog. It is probable that Antoine is thirsty. It is probable that Brian is a lion. It is impossible that if either 'Brian is a lion' or 'Bernhard is a frog' but not both then Greg is yellow. It is certain that if 'Antoine is thirsty' or 'Brian is a lion' or both then Emily is a mouse. There is almost no chance that if 'Bernhard is a frog and Brian is a lion' then John moved to the garden.
It is impossible that 'Greg is yellow and Bernhard is a frog'.
It is impossible that 'Greg is yellow and Bernhard is a frog'.
It is almost certain that 'Greg is yellow and Bernhard is a frog'.

  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.
  0.7::factB.
  0.7::factC.
  %hop1
  0.0::factX:-xor(factC,factA).
  1.0::factY:-or(factB,factC).
  0.02::factZ:-and(factA,factC).

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

  query(conclusion).
  
'Greg is yellow and Bernhard is a frog'.