We believe that Gertrude is a sheep. There is a better than even chance that Lily is a rhino. It is highly likely that Bernhard is a swan. It is likely that if 'Bernhard is a swan and Gertrude is a sheep' then Julius is a swan. It is probably the case that if 'Lily is a rhino' or 'Bernhard is a swan' or both then John went to the office. There is a very good chance that if 'Lily is a rhino and Gertrude is a sheep' then Mary left the football.
There is almost no chance that 'Gertrude is a sheep' or 'John went to the office' or both.
It is highly likely that 'Gertrude is a sheep' or 'John went to the office' or both.
There is almost no chance that 'Gertrude is a sheep' or 'John went to the office' 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
  0.75::factA.
  0.6::factB.
  0.9::factC.
  %hop1
  0.7::factX:-and(factC,factA).
  0.7::factY:-or(factB,factC).
  0.8::factZ:-and(factB,factA).

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

  query(conclusion).
  
'Gertrude is a sheep' or 'John went to the office' or both.