SIC EXTENSION

        [SIC\]SIC EXTENSION [Extension1 ... ExtensionN]

    Without arguments, print the list of extensions used by commands  @  and
    EDIT,  with  precedence  given  from the left to the right. Defaults are
    program dependent: for all Gildas softwares, it  is  the  program  name,
    while  many  user created applications use the generic default extension
    ".pro".

    With one or more arguments, add the input extension(s) at the  beginning
    of  the  list,  i.e.  with  highest precedence. If extension was already
    known, SIC EXTENSION also brings it back at the beginning.