title: SICStus Prolog ignores changes
body: <p>I am pretty new to prolog. Using SICStus, when I make a change to a file that has already been consulted, SICStus does not recognise the changes. Only way is for me to close the window and start it again. But obviously this is not practical as closing the window everytime you make a change to the file is not only annoying but time wasting. I am using Sicstus 4.2.1, the windows version. So far, I have tried the commands consult(file), reconsult(file), compile(file) but none made a difference. SICStus simply ignores the changes made till I close and open the window.</p>
  
  <p>Say, for example, I had the predicate test/2. Then I deleted it and saved the file. And then I type reconsult(file). My expectation was that SICStus will recognise the changes made and say that the predicate does not exist. But it continues as though it exists. Only after I close the window and start all over again will it  rightly complain that the predicate does not exist. </p>
  
  <p>Strangely though, it recognises a newly added predicate with reconsult(file) but if it is changed or deleted, it does not.</p>