.. default-domain:: dynare

##############
Running Dynare
##############

In order to give instructions to Dynare, the user has to write a
*model file* whose filename extension must be ``.mod`` or
``.dyn``. This file contains the description of the model and the
computing tasks required by the user. Its contents are described in
:ref:`model-file`.

.. _dyn-invoc:

Dynare invocation
=================

Once the model file is written, Dynare is invoked using the ``dynare``
command at the MATLAB or Octave prompt (with the filename of the
``.mod`` given as argument).

In practice, the handling of the model file is done in two steps: in
the first one, the model and the processing instructions written by
the user in a *model file* are interpreted and the proper MATLAB or
Octave instructions are generated; in the second step, the program
actually runs the computations. Both steps are triggered automatically
by the ``dynare`` command.

    .. matcomm:: dynare FILENAME[.mod] [OPTIONS…]

    This command launches Dynare and executes the instructions
    included in ``FILENAME.mod``. This user-supplied file contains the
    model and the processing instructions, as described in
    :ref:`model-file`. The options, listed below, can be passed on the
    command line, following the name of the ``.mod`` file or in the
    first line of the ``.mod`` file itself (see below).

    Dynare begins by launching the preprocessor on the ``.mod
    file``. By default (unless the :opt:`use_dll` option has been given to
    ``model``), the preprocessor creates three intermediary files:

    - ``+FILENAME/driver.m``

        Contains variable declarations, and computing tasks.

    - ``+FILENAME/dynamic.m``

        Contains the dynamic model equations. Note that Dynare might
        introduce auxiliary equations and variables (see
        :ref:`aux-variables`). Outputs are the residuals of the
        dynamic model equations in the order the equations were
        declared and the Jacobian of the dynamic model equations. For
        higher order approximations also the Hessian and the
        third-order derivatives are provided. When computing the
        Jacobian of the dynamic model, the order of the endogenous
        variables in the columns is stored in
        ``M_.lead_lag_incidence``. The rows of this matrix represent
        time periods: the first row denotes a lagged (time t-1)
        variable, the second row a contemporaneous (time t) variable,
        and the third row a leaded (time t+1) variable. The columns of
        the matrix represent the endogenous variables in their order
        of declaration. A zero in the matrix means that this
        endogenous does not appear in the model in this time
        period. The value in the ``M_.lead_lag_incidence`` matrix
        corresponds to the column of that variable in the Jacobian of
        the dynamic model. Example: Let the second declared variable
        be ``c`` and the ``(3,2)`` entry of ``M_.lead_lag_incidence``
        be 15. Then the 15th column of the Jacobian is the derivative
        with respect to ``c(+1)``.

    - ``+FILENAME/static.m``

        Contains the long run static model equations. Note that Dynare
        might introduce auxiliary equations and variables (see
        :ref:`aux-variables`). Outputs are the residuals of the static
        model equations in the order the equations were declared and
        the Jacobian of the static equations. Entry ``(i,j)`` of the
        Jacobian represents the derivative of the `i` -th static model
        equation with respect to the `j` -th model variable in declaration
        order.


    These files may be looked at to understand errors reported at the
    simulation stage.

    ``dynare`` will then run the computing tasks by executing
    ``+FILENAME/driver.m``. If a user needs to rerun the computing
    tasks without calling the preprocessor (or without calling the
    :mcomm:`dynare` command), for
    instance because he has modified the script, he just has to type
    the following on the command line:

    .. code-block:: matlab

        >> FILENAME.driver

    A few words of warning are warranted here: under Octave the
    filename of the ``.mod`` file should be chosen in such a way that
    the generated ``.m`` files described above do not conflict with
    ``.m`` files provided by Octave or by Dynare. Not
    respecting this rule could cause crashes or unexpected
    behaviour. In particular, it means that the ``.mod`` file cannot
    be given the name of an Octave or Dynare command. For instance, under
    Octave, it also means that the ``.mod`` file cannot be named
    ``test.mod`` or ``example.mod``.

    .. _quote-note:

    .. note::
       Note on Quotes

       When passing command line options that contain a space (or, under
       Octave, a double quote), you must surround the entire option (keyword
       and argument) with single quotes, as in the following example.

       *Example*

       Call Dynare with options containing spaces

       .. code-block:: matlab

          >> dynare <<modfile.mod>> '-DA=[ i in [1,2,3] when i > 1 ]' 'conffile=C:\User\My Documents\config.txt'

    *Options*

    .. option:: noclearall

        By default, ``dynare`` deletes all the global variables and the
        functions using persistent variables, in order to benefit from the JIT
        (just-in-time) compilation. This option instructs ``dynare`` not to
        clear those.

    .. option:: onlyclearglobals

        By default, ``dynare`` deletes all the global variables and the
        functions using persistent variables, in order to benefit from the JIT
        (just-in-time) compilation. This option instructs ``dynare`` to clear
        only its own global variables (*i.e.* ``M_, options_, oo_,
        estim_params_``, ``dataset_``, ``dataset_info`` and
        ``estimation_info``), leaving the other variables in the workspace, and
        not clearing functions using persistent variables.

    .. option:: debug

        Instructs the preprocessor to write some debugging information
        about the scanning and parsing of the ``.mod`` file.

    .. option:: notmpterms

        Instructs the preprocessor to omit temporary terms in the
        static and dynamic files; this generally decreases
        performance, but is used for debugging purposes since it makes
        the static and dynamic files more readable.

    .. option:: savemacro[=FILENAME]

        Instructs ``dynare`` to save the intermediary file which is obtained
        after macro processing (see :ref:`macro-proc-lang`); the saved output
        will go in the file specified, or if no file is specified in
        ``FILENAME_macroexp.mod``. See the :ref:`note on quotes<quote-note>`
        for info on passing a ``FILENAME`` argument containing spaces.

    .. option:: onlymacro

        Instructs the preprocessor to only perform the
        macro processing step, and stop just after. Useful for
        debugging purposes or for using the macro processor
        independently of the rest of Dynare toolbox.

    .. option:: linemacro

        Instructs the macro preprocessor to include ``@#line`` directives
        specifying the line on which macro directives were encountered and
        expanded from. Only useful in conjunction with :opt:`savemacro
        <savemacro[=FILENAME]>`.

    .. option:: onlymodel

        Instructs the preprocessor to print only information about the
        model in the driver file; no Dynare commands (other than the
        shocks statement and parameter initializations) are printed
        and hence no computational tasks performed. The same
        ancillary files are created as would otherwise be created
        (dynamic, static files, etc.).

    .. option:: nolog

        Instructs Dynare to not create a log file of this run in
        ``FILENAME.log.`` The default is to create the log file.

    .. option:: output=first|second|third

       Instructs the preprocessor to output derivatives of the dynamic model at
       least up to the given order. The `first` option is useful in
       larger models when debugging steady state computation, because it allows
       overriding the default computation and output of dynamic second order derivatives
       in case of the mod-file not containing commands for further computations.

    .. option:: language=matlab|julia

       Instructs the preprocessor to write output for MATLAB or Julia. Default:
       MATLAB

    .. option:: params_derivs_order=0|1|2

        When :comm:`identification`, :comm:`sensitivity` (with
        identification), or :ref:`estimation <estim-comm>` are
        present, this option is used to limit the order of the
        derivatives with respect to the parameters that are calculated
        by the preprocessor. 0 means no derivatives, 1 means first
        derivatives, and 2 means second derivatives. Default: 2

    .. option:: nowarn

        Suppresses all warnings.

    .. option:: notime

        Do not print the total computing time at the end of the driver, and do
        not save that total computing time to ``oo_.time``.

    .. option:: transform_unary_ops

       Transform the following operators in the model block into auxiliary
       variables: ``exp``, ``log``, ``log10``, ``cos``, ``sin``, ``tan``,
       ``acos``, ``asin``, ``atan``, ``cosh``, ``sinh``, ``tanh``, ``acosh``,
       ``asinh``, ``atanh``, ``sqrt``, ``cbrt``, ``abs``, ``sign``,
       ``erf``. Default: no obligatory transformation

    .. option:: json = parse|check|transform|compute

        Causes the preprocessor to output a version of the ``.mod`` file in
        JSON format to ``<<M_.fname>>/model/json/``.
        When the JSON output is created depends on the value
        passed. These values represent various steps of processing in the
        preprocessor.

        If ``parse`` is passed, the output will be written after the parsing of
        the ``.mod`` file to a file called ``FILENAME.json`` but before file
        has been checked (e.g. if there are unused exogenous in the model
        block, the JSON output will be created before the preprocessor exits).

        If ``check`` is passed, the output will be written to a file called
        ``FILENAME.json`` after the model has been checked.

        If ``transform`` is passed, the JSON output of the transformed
        model (maximum lead of 1, minimum lag of -1, expectation
        operators substituted, etc.) will be written to a file called
        ``FILENAME.json`` and the original, untransformed model will
        be written in ``FILENAME_original.json``.

        And if ``compute`` is passed, the output is written after the
        computing pass. In this case, the transformed model is written
        to ``FILENAME.json``, the original model is written to
        ``FILENAME_original.json``, and the dynamic and static files
        are written to ``FILENAME_dynamic.json`` and
        ``FILENAME_static.json``.

    .. option:: jsonstdout

        Instead of writing output requested by ``json`` to files,
        write to standard out, i.e. to the MATLAB/Octave command window
        (and the log-file).

    .. option:: onlyjson

        Quit processing once the output requested by ``json`` has been
        written.

    .. option:: jsonderivsimple

        Print a simplified version (excluding variable name(s) and lag
        information) of the static and dynamic files in
        ``FILENAME_static.json`` and ``FILENAME_dynamic.``.

    .. option:: warn_uninit

        Display a warning for each variable or parameter which is not
        initialized. See :ref:`param-init`, or
        :comm:`load_params_and_steady_state
        <load_params_and_steady_state>` for initialization of
        parameters. See :ref:`init-term-cond`, or
        :comm:`load_params_and_steady_state
        <load_params_and_steady_state>` for initialization of
        endogenous and exogenous variables.

    .. option:: console

        Activate console mode. In addition to the behavior of
        ``nodisplay``, Dynare will not use graphical wait bars for long
        computations.

    .. option:: nograph
       :noindex:

        Activate the ``nograph`` option (see :opt:`nograph`), so that
        Dynare will not produce any graph.

    .. option:: nointeractive

        Instructs Dynare to not request user input.

    .. option:: nopathchange

        By default, Dynare will change MATLAB/Octave’s path if
        ``dynare/matlab`` directory is not on top and if Dynare’s
        routines are overridden by routines provided in other
        toolboxes. If one wishes to override Dynare’s routines, the
        ``nopathchange`` options can be used. Alternatively, the path
        can be temporarily modified by the user at the top of the
        ``.mod`` file (using MATLAB/Octave’s ``addpath`` command).

    .. option:: nopreprocessoroutput

        Prevent Dynare from printing the output of the steps leading up to the
        preprocessor as well as the preprocessor output itself.

    .. option:: mexext=mex|mexw64|mexmaci64|mexmaca64|mexa64

        The mex extension associated with your platform to be used
        when compiling output associated with :opt:`use_dll`.
        Dynare is able to set this automatically, so you should not
        need to set it yourself.

    .. option:: matlabroot=<<path>>

        The path to the MATLAB installation for use with :opt:`use_dll`. Dynare
        is able to set this automatically, so you should not need to set it
        yourself. See the :ref:`note on quotes<quote-note>` for info on
        passing a ``<<path>>`` argument containing spaces.

    .. option:: parallel[=CLUSTER_NAME]

        Tells Dynare to perform computations in parallel. If
        CLUSTER_NAME is passed, Dynare will use the specified cluster
        to perform parallel computations. Otherwise, Dynare will use
        the first cluster specified in the configuration file. See
        :ref:`conf-file`, for more information about the configuration
        file.

    .. option:: conffile=FILENAME

        Specifies the location of the configuration file if it differs from the
        default. See :ref:`conf-file`, for more information about the
        configuration file and its default location. See the :ref:`note on
        quotes<quote-note>` for info on passing a ``FILENAME`` argument
        containing spaces.

    .. option:: parallel_follower_open_mode

        Instructs Dynare to leave the connection to the follower node
        open after computation is complete, closing this connection
        only when Dynare finishes processing.

    .. option:: parallel_test

        Tests the parallel setup specified in the configuration file
        without executing the ``.mod`` file. See :ref:`conf-file`, for
        more information about the configuration file.

    .. option:: parallel_use_psexec=true|false

        For local execution under Windows operating system,
        set ``parallel_use_psexec=false`` to use ``start``
        instead of ``psexec``, to properly allocate affinity when there are
        more than 32 cores in the local machine. This option is also helpful if
        ``psexec`` cannot be executed due to missing administrator privileges. [default=true]

    .. option:: -DMACRO_VARIABLE[=MACRO_EXPRESSION]

        Defines a macro-variable from the command line (the same effect as
        using the Macro directive ``@#define`` in a model file, see
        :ref:`macro-proc-lang`). See the :ref:`note on quotes<quote-note>` for
        info on passing a ``MACRO_EXPRESSION`` argument containing spaces. Note
        that an expression passed on the command line can reference variables
        defined before it. If ``MACRO_EXPRESSION`` is omitted, the variable is
        assigned the ``true`` logical value. Strings assigned to a macro variable
        need to be enclosed in double-quoted strings. This also allows for passing
        single quotes within the strings.

        *Example*

        Call Dynare with command line defines

            .. code-block:: matlab

               >> dynare <<modfile.mod>> -DA=true '-DB="A string with space"' -DC=[1,2,3] '-DD=[ i in C when i > 1 ]' -DE -Ddatafile_name="'my_data_file.mat'"

    .. option:: -I<<path>>

        Defines a path to search for files to be included by the macro
        processor (using the ``@#include`` command). Multiple ``-I`` flags can
        be passed on the command line. The paths will be searched in the order
        that the ``-I`` flags are passed, and the first matching file will be
        used. The flags passed here take priority over those passed to
        ``@#includepath``. See the :ref:`note on quotes<quote-note>` for info
        on passing a ``<<path>>`` argument containing spaces.

    .. option:: nostrict

        Allows Dynare to issue a warning and continue processing when

        1. there are more endogenous variables than equations.
        2. an undeclared symbol is assigned in ``initval`` or ``endval``.
        3. an undeclared symbol is found in the ``model`` block in
           this case, it is automatically declared exogenous.
        4. exogenous variables were declared but not used in the
           ``model`` block.

    .. option:: fast

        Don’t rewrite the output files otherwise written to the disk by the preprocessor
        when re-running the same model file while the lists of variables and the equations
        haven’t changed. Note that the whole model still needs to be preprocessed. This option
        is most useful with model option :opt:`use_dll`, because
        the time-consuming compilation of the MEX files will be skipped. We use a 32
        bit checksum, stored in ``<model filename>/checksum``. There
        is a very small probability that the preprocessor misses a
        change in the model. In case of doubt, re-run without the fast
        option.

    .. option:: minimal_workspace

        Instructs Dynare not to write parameter assignments to
        parameter names in the ``.m`` file produced by the
        preprocessor. This is potentially useful when running
        ``dynare`` on a large ``.mod`` file that runs into workspace
        size limitations imposed by MATLAB.

    .. option:: compute_xrefs

        Tells Dynare to compute the equation cross-references, writing
        them to the output ``.m`` file.

    .. option:: stochastic

        By default, if no Dynare commands related to stochastic models
        (``stoch_simul``, ``estimation``, ``osr``, ``discretionary_policy``,
        ``calib_smoother``, ``identification``, ``method_of_moments``,
        ``sensitivity``) are present in the ``.mod`` file,
        Dynare treats the model to be solved as deterministic.
        This option instructs Dynare that the model to be solved is stochastic
        and that there is an implicit conditional expectation operator in the
        model equations. It modifies the internal handling of
        nonlinear forward-looking terms to account for Jensen's Inequality.
        This option is useful when the user wants to work with a stochastic
        model but does not want to use any of the stochastic Dynare
        commands, e.g., due to calling Matlab functions directly.

    .. _exclude_eqs:

    .. option:: exclude_eqs=<<equation_tags_to_exclude>>

       Tells Dynare to exclude all equations specified by the argument. As a
       ``.mod`` file must have the same number of endogenous variables as
       equations, when `exclude_eqs` is passed, certain rules are followed for
       excluding endogenous variables. If the ``endogenous`` tag has been set
       for the excluded equation, the variable it specifies is
       excluded. Otherwise, if the left-hand side of the excluded equation is
       an expression that contains only one endogenous variable, that variable
       is excluded. If neither of these conditions hold, processing stops with
       an error. If an endogenous variable has been excluded by the
       `exclude_eqs` option, and it exists in an equation that has not been
       excluded, it is transformed into an exogenous variable.

       To specify which equations to exclude, you must pass the argument
       ``<<equation_tags_to_exclude>>``. This argument takes either a list of
       equation tags specifying the equations to be excluded or a filename that
       contains those tags.

       If ``<<equation_tags_to_exclude>>`` is a list of equation tags, it can
       take one of the following forms:

       #. Given a single argument, e.g. ``exclude_eqs=eq1``, the equation with
          the tag ``[name='eq1']`` will be excluded. Note that if there is a
          file called ``eq1`` in the current directory, Dynare will instead
          try to open this and read equations to exclude from it (see info on
          filename argument to ``exclude_eqs`` below). Further note that if the
          tag value contains a space, you must use the variant specified in 2
          below, i.e. ``exclude_eqs=[eq 1]``.
       #. Given two or more arguments, e.g. ``exclude_eqs=[eq1, eq 2]``, the
          equations with the tags ``[name='eq1']`` and ``[name='eq 2']`` will
          be excluded.
       #. If you'd like to exclude equations based on another tag name (as
          opposed to the default ``name``), you can pass the argument as either
          e.g. ``exclude_eqs=[tagname=a tag]`` if a single equation with tag
          ``[tagname='a tag']`` is to be excluded or as
          e.g. ``exclude_eqs=[tagname=(a tag, 'a tag with a, comma')]`` if more
          than one equation with tags ``[tagname='a tag']`` and ``[tagname='a
          tag with a, comma']`` will be excluded (note the parenthesis, which
          are required when more than one equation is specified). Note that if
          the value of a tag contains a comma, it must be included inside
          single quotes.

       If ``<<equation_tags_to_exclude>>`` is a filename, the file can take one
       of the following forms:

       #. One equation per line of the file, where every line represents the
          value passed to the ``name`` tag. e.g., a file such as::

             eq1
             eq 2

          would exclude equations with tags ``[name='eq1']`` and ``[name='eq
          2']``.
       #. One equation per line of the file, where every line after the first
          line represents the value passed to the tag specified by the first
          line. e.g., a file such as::

             tagname=
             a tag
             a tag with a, comma

          would exclude equations with tags ``[tagname='a tag']`` and
          ``[tagname='a tag with a, comma']``. Here note that the first line
          must end in an equal sign.

    .. option:: include_eqs=<<equation_tags_to_include>>

       Tells Dynare to run with only those equations specified by the
       argument; in other words, Dynare will exclude all equations not
       specified by the argument. The argument ``<<equation_tags_to_include>>``
       is specified in the same way as the argument to :ref:`exclude_eqs
       <exclude_eqs>`. The functionality of ``include_eqs`` is to find which
       equations to exclude then take actions in accord with :ref:`exclude_eqs
       <exclude_eqs>`.

    .. option:: use_dll
       :noindex:

       Instructs the preprocessor to create dynamic loadable libraries (DLL)
       containing the model equations and derivatives, instead of writing
       those in M-files. This is equivalent to the :opt:`use_dll` option of
       the ``model`` block.

    .. option:: nocommutativity

       This option tells the preprocessor not to use the commutativity of
       addition and multiplication when looking for common subexpressions. As a
       consequence, when using this option, equations in various outputs
       (LaTeX, JSON…) will appear as the user entered them (without terms or
       factors swapped). Note that using this option may have a performance
       impact on the preprocessing stage, though it is likely to be small.

    These options can be passed to the preprocessor by listing them
    after the name of the ``.mod`` file. They can alternatively be
    defined in the first line of the ``.mod`` file, this avoids typing
    them on the command line each time a ``.mod`` file is to be
    run. This line must be a Dynare one-line comment (i.e. must begin with ``//``)
    and the options must be whitespace separated between ``--+ options:``
    and ``+--``. Note that any text after the ``+--`` will be
    discarded. As in the command line, if an option admits a value the
    equal symbol must not be surrounded by spaces. For instance ``json
    = compute`` is not correct, and should be written
    ``json=compute``. The ``nopathchange`` option cannot be specified in
    this way, it must be passed on the command-line.

    *Output*

    Depending on the computing tasks requested in the ``.mod`` file,
    executing the ``dynare`` command will leave variables containing
    results in the workspace available for further processing. More
    details are given under the relevant computing tasks. The
    ``M_``, ``oo_``, and ``options_`` structures are saved in a file
    called ``FILENAME_results.mat`` located in the ``MODFILENAME/Output`` folder.
    If they exist, ``estim_params_``,
    ``dataset_``, ``oo_recursive_`` and
    ``estimation_info`` are saved in the same file. Note that MATLAB
    by default only allows ``.mat`` files up to 2GB. You can lift this
    restriction by enabling the ``save -v7.3`` option in
    ``Preferences -> General -> MAT-Files``.

    .. matvar:: M_

        Structure containing various information about the model.

    .. matvar:: options_

        Structure contains the values of the various options used by
        Dynare during the computation.

    .. matvar:: oo_

        Structure containing the various results of the computations.

    .. matvar:: dataset_

        A ``dseries`` object containing the data used for estimation.

    .. matvar:: oo_recursive_

        Cell array containing the ``oo_`` structures obtained when
        estimating the model for the different samples when performing
        recursive estimation and forecasting. The ``oo_`` structure
        obtained for the sample ranging to the `i` -th observation is
        saved in the `i` -th field. The fields for non-estimated
        endpoints are empty.

    .. matvar:: oo_.time

        Total computing time of the Dynare run, in seconds. This field is not
        set if the :opt:`notime` option has been used.

    *Example*

    Call Dynare from the MATLAB or Octave prompt, without or with options:

            .. code-block:: matlab

               >> dynare ramst
               >> dynare ramst.mod savemacro

    Alternatively the options can be passed in the first line of
    ``ramst.mod``:

            .. code-block:: dynare

               // --+ options: savemacro, json=compute +--

    and then call Dynare without passing options on the command line:

            .. code-block:: matlab

               >> dynare ramst




Dynare hooks
============

It is possible to call pre and post Dynare preprocessor hooks written
as MATLAB scripts. The script ``MODFILENAME/hooks/priorprocessing.m``
is executed before the call to Dynare’s preprocessor, and can be used
to programmatically transform the mod file that will be read by the
preprocessor. The script ``MODFILENAME/hooks/postprocessing.m`` is
executed just after the call to Dynare’s preprocessor, and can be used
to programmatically transform the files generated by Dynare’s
preprocessor before actual computations start. The pre and/or post
Dynare preprocessor hooks are executed if and only if the
aforementioned scripts are detected in the same folder as the
model file, ``FILENAME.mod``.


Understanding Preprocessor Error Messages
=========================================

If the preprocessor runs into an error while processing your ``.mod``
file, it will issue an error. Due to the way that a parser works,
sometimes these errors can be misleading. Here, we aim to demystify
these error messages.

The preprocessor issues error messages of the form:

   #. ``ERROR: <<file.mod>>: line A, col B: <<error message>>``
   #. ``ERROR: <<file.mod>>: line A, cols B-C: <<error message>>``
   #. ``ERROR: <<file.mod>>: line A, col B - line C, col D: <<error message>>``

The first two errors occur on a single line, with error two spanning
multiple columns. Error three spans multiple rows.

Often, the line and column numbers are precise, leading you directly
to the offending syntax. Infrequently however, because of the way the
parser works, this is not the case. The most common example of
misleading line and column numbers (and error message for that matter)
is the case of a missing semicolon, as seen in the following example::

    varexo a, b
    parameters c, ...;

In this case, the parser doesn’t know a semicolon is missing at the
end of the ``varexo`` command until it begins parsing the second line
and bumps into the ``parameters`` command. This is because we allow
commands to span multiple lines and, hence, the parser cannot know
that the second line will not have a semicolon on it until it gets
there. Once the parser begins parsing the second line, it realizes
that it has encountered a keyword, ``parameters``, which it did not
expect. Hence, it throws an error of the form: ``ERROR: <<file.mod>>:
line 2, cols 0-9: syntax error, unexpected PARAMETERS``. In this case,
you would simply place a semicolon at the end of line one and the
parser would continue processing.

It is also helpful to keep in mind that any piece of code that does not violate
Dynare syntax, but at the same time is not recognized by the parser, is interpreted
as native MATLAB code. This code will be directly passed to the driver script.
Investigating the ``driver.m`` file then helps with debugging. Such problems most often
occur when defined variable or parameter names have been misspelled so that Dynare's
parser is unable to recognize them.
