@1
'ShowErrors' activates the "display-errors" mode of the syntax
directed editor. Within this mode all parts of the current
document which are erronous with respect to its context-
sensitive syntax (static semantics) are marked by under-
lying a black background to a reverse presentation. Use 
'FirstMarker', 'NextMarker', and 'PrevMarker' to navigate
between erronous parts of the document. 

Selecting the command group of 'ShowError' for the first
time automatically activates this command.

Activating 'ShowErrors' for the first time after a couple
of changes within the current document may cause a short
delay: Analysis of all parts of the document affected by
these changes occurs now! Note, that the time necessary
for analysing document changes is proportional to the
maximum(no. of changed increments, no. of erroneous inc.).
Therefore, avoid documents containing many errors by
removing errors as soon as possible.

Select 'HideErrors' to suppress markings and to deactivate
the incrementally working analysis.

--> 'HideErrors', 'FirstMarker', ...
    'ShowWarnings', 'HideWarnings'
@2
'HideErrors' deactivates the "display-errors" mode of the
syntax-directed editor. This command must be used to suppress 
error markings and to deactivate the incrementally working
analysis of a document's contextsensitive correctness.

--> 'ShowErrors', 'FirstMarker', ...
    'ShowWarnings', 'HideWarnings'
@3
'ShowWarnings' activates the "display-errors&warnings" mode
of the syntax-directed editor. Like in the "display-errors"
mode all parts of the current document which are erronous
with respect to its contextsensitive syntax are marked by
underlying a black background to a reverse presentation.
Additionally, a grey background marks possible inconsistencies
or incomplete parts within a document.

Select 'HideWarnings' to suppress grey markings and use
'HideErrors' to suppress black markings and to deactivate
the incrementally working analysis.

--> 'HideWarnings', 'FirstMarker', ...
    'ShowErrors', 'HideErrors'
@4
'HideWarnings' deactivates the "display-errors&warnings" mode
of the syntax-directed editor. This command must be used to
suppress grey markings and to enter the editor's "display-
errors" mode.

--> 'ShowWarnings', 'FirstMarker', ...
    'ShowErrors', 'HideErrors'
@5
'HideChangedAppls' deletes the markers of the command 'RenameWithAppls'.
Selecting another analysis mode ('ShowErrors', ...) has the same effect.

--> 'RenameWithAppls', 'ShowErrors', 'ShowWarnings', 'FirstMarker', ...
@6
'RenameWithAppls' activates an emacs-like text editor (press the
"Help" key within emacs mode for further information about
key bindings etc.) for changing the declaration and all applied
occurrences of an identifier. Note that due to nested scopes
or previously unbound applied occurrences changing the name of a
declaration and of its applied occurrences may not preserve all
bindings of applied occurrences.

In the case of changed bindings, a new analysis mode is activated
and all applied occurrences which lost their binding to the current
declaration or are now bound to a new declaration are marked.

--> 'Modify', 'HideChangedAppls', 'ShowErrors', 'FirstMarker', ...
@9
'FirstMarker' selects the first marked increment 
in the presentation as the new current increment 
and displays its message text.

--> 'ShowErrors', 'ShowWarnings', 'ShowMessage',
    'NextMarker', 'PrevMarker'
@10
'NextMarker' selects the next marked increment in 
the presentation as the new current increment and 
displays its message text.

--> 'ShowErrors',  'ShowWarnings', 'howMessage',
    'FirstMarker', 'PrevMarker'
@11
'PrevMarker' selects the previous marked increment 
in the presentation as the new current increment 
and displays its message text.

--> 'ShowErrors',  'ShowWarnings', 'ShowMessage',
    'FirstMarker', 'NextMarker'
@12
'ShowMessage' displays the message belonging to
the next marked ancestor increment of the
current increment (e.g. the message of the
currently selected increment itself).

--> 'ShowErrors',  'ShowWarnings', 'FirstMarker', 
    'NextMarker',  'PrevMarker'
