It is probably not the case that Bernhard is a rhino. There is a better than even chance that John went to the garden. It is probably the case that Gertrude is a cat. There is a very good chance that if 'Bernhard is a rhino' or 'John went to the garden' or both then Greg is white. It is probable that if either 'Gertrude is a cat' or 'Bernhard is a rhino' but not both then Julius is yellow. We believe that if either 'John went to the garden' or 'Bernhard is a rhino' but not both then Sandra dropped the milk.
It is likely that 'Bernhard is a rhino and Sandra dropped the milk'.
It is highly unlikely that 'Bernhard is a rhino and Sandra dropped the milk'.
It is likely that 'Bernhard is a rhino and Sandra dropped the milk'.

  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.
  0.6::factB.
  0.7::factC.
  %hop1
  0.8::factX:-or(factA,factB).
  0.7::factY:-xor(factC,factA).
  0.75::factZ:-xor(factB,factA).

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

  query(conclusion).
  
'Bernhard is a rhino and Sandra dropped the milk'.