It is probable that Mary grabbed the milk. It is impossible that Brian is yellow. It is impossible that Bernhard is a rhino. It is highly unlikely that if 'Bernhard is a rhino' or 'Mary grabbed the milk' or both then John moved to the garden. It is likely that if either 'Brian is yellow' or 'Bernhard is a rhino' but not both then Greg is a swan. It is almost certain that if 'Brian is yellow' or 'Bernhard is a rhino' or both then Lily is a frog.
It is likely that 'Mary grabbed the milk' or 'Greg is a swan' or both.
It is likely that 'Mary grabbed the milk' or 'Greg is a swan' or both.
There is almost no chance that 'Mary grabbed the milk' or 'Greg is a swan' 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
  0.7::factA.
  0.0::factB.
  0.0::factC.
  %hop1
  0.05::factX:-or(factC,factA).
  0.7::factY:-xor(factB,factC).
  0.95::factZ:-or(factB,factC).

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

  query(conclusion).
  
'Mary grabbed the milk' or 'Greg is a swan' or both.