It is probable that Gertrude is a sheep. There is a better than even chance that Lily is a rhino. It is unlikely that Julius is a frog. It is probable that if 'Lily is a rhino and Gertrude is a sheep' then Brian is white. It is probably the case that if either 'Lily is a rhino' or 'Gertrude is a sheep' but not both then Greg is a rhino. It is probably the case that if 'Julius is a frog' or 'Lily is a rhino' or both then Sandra got the milk.
It is improbable that 'Sandra got the milk and Greg is a rhino'.
It is improbable that 'Sandra got the milk and Greg is a rhino'.
It is certain that 'Sandra got the milk and Greg is a rhino'.

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

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

  query(conclusion).
  
'Sandra got the milk and Greg is a rhino'.