It is impossible that Greg is a rhino. We believe that Mary discarded the milk. It is almost certain that John went to the office. There is a better than even chance that if 'John went to the office' or 'Greg is a rhino' or both then Emily is a mouse. It is improbable that if 'Mary discarded the milk' or 'Greg is a rhino' or both then Winona is a sheep. There is a very good chance that if 'Mary discarded the milk' or 'Greg is a rhino' or both then Brian is a swan.
It is impossible that 'Greg is a rhino and Winona is a sheep'.
It is impossible that 'Greg is a rhino and Winona is a sheep'.
Chances are about even that 'Greg is a rhino and Winona is a sheep'.

  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
  0.0::factA.
  0.75::factB.
  0.95::factC.
  %hop1
  0.6::factX:-or(factC,factA).
  0.1::factY:-or(factB,factA).
  0.8::factZ:-or(factB,factA).

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

  query(conclusion).
  
'Greg is a rhino and Winona is a sheep'.