MathML: refactor and extend.

Only wrap displayed math in <mtable> if there are multiple rows.
Fix alignment and spacing in multi-line equations.
Fix size commands for extensible delimiters.

Add support for commands \displaylimits, \mspace, \intop, \ointop.

math.get(): new method, return attribute or optional default.
tex_token(): don't skip leading whitespace, don't return groups
tex_group(): new function -- return first group or token and remainder.
tex_group_or_token(): new function

git-svn-id: https://svn.code.sf.net/p/docutils/code/trunk@8760 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

5 files changed, 620 insertions, 451 deletions

diff --git a/docutils/docs/ref/rst/mathematics.txt b/docutils/docs/ref/rst/mathematics.txt
index 715250826..ab4cadd20 100644
--- a/docutils/docs/ref/rst/mathematics.txt
+++ b/docutils/docs/ref/rst/mathematics.txt
@@ -6,34 +6,16 @@ LaTeX syntax for mathematics
 .. default-role:: math
 .. |latex| replace:: L\ :sup:`A`\ T\ :sub:`E`\ X
 
+:abstract: Docutils supports mathematical content with a `"math"
+           directive`__ and `role`__. The input format is *LaTeX math
+           syntax*\ [#math-syntax]_ with support for Unicode symbols.
+
 .. sectnum::
 .. contents::
 
-Introduction
-============
-
-Since version 0.8, Docutils supports mathematical content with a `"math"
-directive`__ and `role`__.
-The input format is *LaTeX math syntax*\ [#math-syntax]_ with support for
-Unicode symbols.
-
-
-.. [#math-syntax] The supported LaTeX commands include AMS extensions
-   (see, e.g., the `Short Math Guide`_).
-
-   The support is limited to a subset of *LaTeX math* by the conversion
-   required for many output formats.  For HTML, the `math_output`_
-   configuration setting (or the corresponding ``--math-output`` command
-   line option) selects between alternative output formats with different
-   subsets of supported elements. If a writer does not support math
-   typesetting, the content is inserted verbatim.
-
 __ https://docutils.sourceforge.io/docs/ref/rst/directives.html#math
 __ https://docutils.sourceforge.io/docs/ref/rst/roles.html#math
-.. _Short Math Guide:
-   http://mirrors.ctan.org/info/short-math-guide/short-math-guide.pdf
-.. _math_output:
-   https://docutils.sourceforge.io/docs/user/config.html#math-output
+
 
 Inline formulas and displayed equations
 =======================================
@@ -89,18 +71,34 @@ Displayed equations can use ``\\`` and ``&`` for line shifts and alignments::
 
   .. math::
 
-     a & = (x + y)^2 \\
-       & = x^2 + 2xy + y^2
+   a &= (x + y)^2         &\qquad b &= (x - y)^2 \\
+     &= x^2 + 2xy + y^2   &        &= x^2 - 2xy + y^2
 
 LaTeX output will wrap it in an ``align*`` environment.
 The result is:
 
 .. math::
 
-   a & = (x + y)^2 \\
-     & = x^2 + 2xy + y^2
+   a &= (x + y)^2         &  b &= (x - y)^2 \\
+     &= x^2 + 2xy + y^2   &    &= x^2 - 2xy + y^2
+
+
+.. [#math-syntax] The supported LaTeX commands include AMS extensions
+   (see, e.g., the `Short Math Guide`_).
+
+   The support is limited to a subset of *LaTeX math* by the conversion
+   required for many output formats.  For HTML, the `math_output`_
+   configuration setting (or the corresponding ``--math-output`` command
+   line option) selects between alternative output formats with different
+   subsets of supported elements. If a writer does not support math
+   typesetting, the content is inserted verbatim.
 
-.. _hyperlink references: ../ref/rst/restructuredtext.html#hyperlink-references
+.. _hyperlink references:
+   ../ref/rst/restructuredtext.html#hyperlink-references
+.. _Short Math Guide:
+   http://mirrors.ctan.org/info/short-math-guide/short-math-guide.pdf
+.. _math_output:
+   https://docutils.sourceforge.io/docs/user/config.html#math-output
 
 
 Mathematical symbols
@@ -183,6 +181,8 @@ Use ``.`` for "empty" delimiters:
 
 .. math:: A = \left . \frac{1}{1-n}\, \right |_{n=0}^\infty
 
+See also the commands for fixed `delimiter sizes`_ below.
+
 The following symbols extend when used with ``\left`` and ``\right``:
 
 Pairing delimiters
@@ -214,6 +214,8 @@ incorrect spacing, e.g., ``|k|=|-k|`` produces `|k| = |−k|` and
 `\lvert -k\rvert` and `\lvert\sin(x)\rvert`, prevent this problem
 (in LaTeX and MathJax).
 
+.. TODO: fix spacing before unary minus (see also cases example below).
+
 Vertical Arrows
 ~~~~~~~~~~~~~~~
 .. class:: colwidths-auto
@@ -261,7 +263,7 @@ Greek letters
 -------------
 
 In LaTeX, the default font for capital Greek letters is upright/roman.
-Italic capital Greek letters can be obtained by loading a `package
+*Italic* capital Greek letters can be obtained by loading a `package
 providing the "ISO" math style`__. They are used by default in MathML.
 
 Greek letters that have Latin look-alikes are rarely used in math
@@ -289,15 +291,14 @@ Letterlike symbols
 ------------------
 .. class:: colwidths-auto
 
-========== ============  ============= ===============  ========= ===========  =========== =============
-`\aleph`   ``\aleph``    `\forall`     ``\forall``      `\hbar`   ``\hbar``    `\ell`      ``\ell``
-`\beth`    ``\beth``     `\complement` ``\complement``  `\hslash` ``\hslash``  `\wp`       ``\wp``
-`\gimel`   ``\gimel``    `\exists`     ``\exists``      `\Im`     ``\Im``      `\Re`       ``\Re``
-`\daleth`  ``\daleth``   `\Finv`       ``\Finv``        `\imath`  ``\imath``   `\circledR` ``\circledR``
-`\partial` ``\partial``  `\Game`       ``\Game``        `\Bbbk`   ``\Bbbk``    `\circledS` ``\circledS``
-`\eth`     ``\eth``                                                            `\mho`      ``\mho``
-========== ============  ============= ===============  ========= ===========  =========== =============
-
+  ============= ===============  ========== ============  ========== ============  =========== =============
+  `\forall`     ``\forall``      `\aleph`   ``\aleph``    `\hbar`    ``\hbar``     `\ell`      ``\ell``
+  `\complement` ``\complement``  `\beth`    ``\beth``     `\hslash`  ``\hslash``   `\wp`       ``\wp``
+  `\exists`     ``\exists``      `\gimel`   ``\gimel``    `\Im`      ``\Im``       `\Re`       ``\Re``
+  `\Finv`       ``\Finv``        `\daleth`  ``\daleth``   `\imath`   ``\imath``    `\circledR` ``\circledR``
+  `\Game`       ``\Game``        `\partial` ``\partial``  `\jmath`   ``\jmath``    `\circledS` ``\circledS``
+  `\mho`        ``\mho``         `\eth`     ``\eth``      `\Bbbk`    ``\Bbbk``
+  ============= ===============  ========== ============  ========== ============  =========== =============
 
 Mathematical Alphabets
 ----------------------
@@ -400,7 +401,6 @@ Punctuation
 .. [#] Punctuation (not ratio):
        Compare spacing in `a\colon b\to c` to `a:b = c`.
 
-
 Relation symbols
 ----------------
 
@@ -577,12 +577,12 @@ The ``matrix`` and ``cases`` environments can also contain ``\\`` and
 ``&``::
 
   .. math::
-     \left(\begin{matrix} a & b \\ c & d \end{matrix}\right)
+     \left ( \begin{matrix} a & b \\ c & d \end{matrix}\right)
 
 Result:
 
 .. math::
-   \left(\begin{matrix} a & b \\ c & d \end{matrix}\right)
+     \left ( \begin{matrix} a & b \\ c & d \end{matrix} \right)
 
 The environments ``pmatrix``, ``bmatrix``, ``Bmatrix``, ``vmatrix``, and
 ``Vmatrix`` have (respectively) ( ), [ ], { }, \| \|, and `\Vert\ \Vert`
@@ -602,8 +602,8 @@ matrix.
 For piecewise function definitions there is a ``cases`` environment:
 
 .. math:: \mathrm{sgn}(x) = \begin{cases}
-                               -1 & x<0\\
-                                1 & x>0
+                              \,          -1 & x<0\\
+                              \,\phantom{-}1 & x>0
                             \end{cases}
 
 Spacing commands
@@ -614,22 +614,25 @@ commands:
 
 .. class:: colwidths-auto
 
-  =====================  ========  =======================
-  :m:`3\qquad8`                    ``3\qquad8`` (2em)
-  :m:`3\quad8`                     ``3\quad8``  (1em)
-  :m:`3~8`               ``3~8``   ``3\nobreakspace8``
-  :m:`3\ 8`              ``3\ 8``  escaped space
-  :m:`3\;8`              ``3\;8``  ``3\thickspace8``
-  :m:`3\:8`              ``3\:8``  ``3\medspace8``
-  :m:`3\,8`              ``3\,8``  ``3\thinspace8``
-  :m:`3  8`              ``3  8``  regular space (ignored)
-  :m:`3\!8`              ``3\!8``  ``3\negthinspace8``
-  :m:`3\negmedspace8`              ``3\negmedspace8``
-  :m:`3\negthickspace8`            ``3\negthickspace8``
-  `3\hspace{1ex}8`                 ``3\hspace{1ex}8``
-  =====================  ========  =======================
-
-Whitespace is ignored in LaTeX math mode.
+  ======================  ========  =====================  ==================
+  :m:`3\qquad |`                    ``3\qquad |``          = 2em
+  :m:`3\quad |`                     ``3\quad |``           = 1em
+  :m:`3~|`                ``3~|``   ``3\nobreakspace |``
+  :m:`3\ |`               ``3\ |``                         escaped space
+  :m:`3\;|`               ``3\;|``  ``3\thickspace |``
+  :m:`3\:|`               ``3\:|``  ``3\medspace |``
+  :m:`3\,|`               ``3\,|``  ``3\thinspace |``
+  :m:`3  |`               ``3  |``                         regular space [#]_
+  :m:`3\!|`               ``3\!|``  ``3\negthinspace |``
+  :m:`3\negmedspace |`              ``3\negmedspace |``
+  :m:`3\negthickspace |`            ``3\negthickspace |``
+  `3\hspace{1ex}|`                  ``3\hspace{1ex}|``     custom length
+  `3\mspace{20mu}|`                 ``3\mspace{20mu}|``    custom length [#]_
+  ======================  ========  =====================  ==================
+
+.. [#] Whitespace characters are ignored in LaTeX math mode.
+.. [#] Unit must be 'mu' (1 mu = 1/18em).
+
 Negative spacing does not work with MathML (in Firefox 78).
 
 There are also three commands that leave a space equal to the height and
@@ -638,8 +641,8 @@ wide and high as three X’s:
 
 .. math:: \frac{\phantom{XXX}+1}{XXX-1}
 
-The commands ``\hphantom`` and ``\vphantom`` insert space with the heigth
-rsp. width of the argument. They are not supported with `math_output`_
+The commands ``\hphantom`` and ``\vphantom`` insert space with the
+width or height of the argument. They are not supported with `math_output`_
 MathML.
 
 Roots
@@ -668,7 +671,8 @@ Fractions and related constructions
 ===================================
 
 The ``\frac`` command takes two ar guments, numerator and denominator,
-and typesets them in normal fraction form. Use ``\dfrac`` or ``\tfrac`` to
+and typesets them in normal fraction form. For example, ``U = \frac{R}{I}``
+produces `U = \frac{R}{I}`. Use ``\dfrac`` or ``\tfrac`` to
 force text style and display style respectively.
 
 .. math:: \frac{x+1}{x-1}  \quad
@@ -689,15 +693,17 @@ prints
 The ``\cfrac`` command for continued fractions uses displaystyle and
 padding for sub-fractions:
 
-.. math:: \cfrac{1}{\sqrt{2}+
-          \cfrac{1}{\sqrt{2}+
-          \cfrac{1}{\sqrt{2}+\dotsb
-          }}}
-          \text{ vs. }
-          \frac{1}{\sqrt{2}+
-          \frac{1}{\sqrt{2}+
-          \frac{1}{\sqrt{2}+\dotsb
-          }}}
+.. math:: \frac{\pi}{4} = 1 + \cfrac{1^2}{
+                              2 + \cfrac{3^2}{
+                                  2 + \cfrac{5^2}{
+                                      2 + \cfrac{7^2}{2 + \cdots}
+                              }}}
+          \qquad \text{vs.}\qquad
+          \frac{\pi}{4} = 1 + \frac{1^2}{
+                              2 + \frac{3^2}{
+                                  2 + \frac{5^2}{
+                                      2 + \frac{7^2}{2 + \cdots}
+                              }}}
 
 It supports the optional argument ``[l]`` or ``[r]`` for
 left or right placement of the numerator:
@@ -775,11 +781,14 @@ Whitespace is kept inside the argument:
 .. Math:: f_{[x_{i-1},x_i]} \text{ is monotonic for }  i = 1,\,…,\,c+1
 
 
-``$`` signs can be used for math commands inside the text, e.g.
+The text may contain math commands wrapped in ``$`` signs, e.g.
+
+.. math:: (-1)^{n_i} = \begin{cases} -1 \quad \text{if $n_i$ is odd} \\
+                                     +1 \quad \text{if $n_i$ is even.}
+                       \end{cases}
+
+.. TODO ignore {}, handle text-mode commands
 
-.. math:: (-1)^n = \begin{cases} -1 \quad \text{if $n$ is odd} \\
-                                 +1 \quad \text{if $n$ is even.}
-                   \end{cases}
 
 .. TODO: ``\mod`` and its relatives
          --------------------------
@@ -806,8 +815,18 @@ similar symbols like
 
 move to index postions: `\lim_{n\to\infty} \sum_1^n \frac{1}{n}`.
 
-The commands ``\limits`` and ``\nolimits`` override the automatic
-placement of the limits; ``\displaylimits`` means to use standard
+Altering the placement of limits
+--------------------------------
+
+The commands ``\intop`` and ``\ointop`` produce integral signs with
+limits as in sums and similar: `\intop_0^1`, `\ointop_c` and
+
+.. math:: \intop_0^1 \quad \ointop_c
+             \quad \text{vs.} \quad
+          \int^1_0   \quad \oint_c
+
+The commands ``\limits`` and ``\nolimits`` override the default placement
+of the limits for any operator; ``\displaylimits`` forces standard
 positioning as for the \sum command. They should follow immediately after
 the operator to which they apply.
 
@@ -859,11 +878,15 @@ yields
    after the opening bracket.
 
 
-Appendix: Tests
-===============
+Appendix
+========
+
+Tests
+-----
+
 
 Font changes
-------------
+~~~~~~~~~~~~
 
 Math alphabet macros change the default alphabet ("mathvariant" in
 MathML), leaving some symbols unchanged:
@@ -879,6 +902,7 @@ Unicode supports the following blackboard-bold characters:
 `\mathbb{a \ldots z A \ldots Z 0 \ldots 9
 \mathbb\Gamma \mathbb{\Pi} \mathbb {\Sigma} \mathbb\gamma \mathbb\pi}`.
 
+
 Inferred <mrow>s in MathML
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -888,11 +912,11 @@ formed from all their children.
 
 .. math:: a = \sqrt 2 + x, b = \sqrt{1+x^2}, c = \sqrt\frac{\sin(x)}{23},
 
-
 inline: :math:`a = \sqrt 2 + x, b = \sqrt{1+x^2}, c = \sqrt\frac{\sin(x)}{23}`.
 
+
 Scripts and Limits
-------------------
+~~~~~~~~~~~~~~~~~~
 
 Accents should be nearer to the base (in MathML Firefox 78, it's vice versa!):
 `\bar a \overline a, \bar l \overline l, \bar i \overline i`.
@@ -902,4 +926,52 @@ Sub- and superscript may be given in any order:
 
 Double exponent: `x^{10^4}`, `r_{T_\mathrm{in}}` and `x_i^{n^2}`.
 
-Binary vs. unary minus operator: `a - b = -c`
+
+Nested groups
+~~~~~~~~~~~~~
+
+tex-token returns "{" for nested groups:
+
+.. math:: \text{das ist ein  {toller} text (unescaped \{ and \} is
+                ignored by LaTeX)}
+
+Big delimiters
+~~~~~~~~~~~~~~
+
+Test ``\left``, ``\right``, and the  \bigl/\bigr, … size commands
+with extensible delimiters.
+
+.. math::
+   \left.(b\right)\ \bigl(b\Bigr)\ \biggl(b\Biggr)
+   \quad
+   \left.[b\right]\ \bigl[b\Bigr]\ \biggl[b\Biggr]
+   \quad
+   \left.\{b\right \} \ \bigl\{b\Bigr \} \ \biggl\{b\Biggr \}
+   \quad
+   \left.\langle b\right\rangle\ \bigl\langle b\Bigr\rangle\ \biggl\langle b\Biggr\rangle
+   \quad
+   \left.\lceil b\right\rceil\ \bigl\lceil b\Bigr\rceil\ \biggl\lceil b\Biggr\rceil
+
+   \left.\lfloor b\right\rfloor\ \bigl\lfloor b\Bigr\rfloor\ \biggl\lfloor b\Biggr\rfloor
+   \quad
+   \left.\lgroup b\right\rgroup\ \bigl\lgroup b\Bigr\rgroup\ \biggl\lgroup b\Biggr\rgroup
+   \quad
+   \left.\lmoustache b\right\rmoustache\ \bigl\lmoustache b\Bigr\rmoustache\ \biggl\lmoustache b\Biggr\rmoustache
+   \quad
+   \left.\lvert b\right\rvert\ \bigl\lvert b\Bigr\rvert\ \biggl\lvert b\Biggr\rvert
+   \quad
+   \left.\lVert b\right\rVert\ \bigl\lVert b\Bigr\rVert\ \biggl\lVert b\Biggr\rVert
+
+   \left.|b\right\|\ \bigl|b\Bigr\|\ \biggl|b\Biggr\|
+   \quad
+   \left./b\right\backslash\ \bigl/b\Bigr\backslash\ \biggl/b\Biggr\backslash
+   \quad
+   \left.(b\right)\ \bigl(b\Bigr)\ \biggl(b\Biggr)
+   \quad
+   \left.\arrowvert b\right\Arrowvert\ \bigl\arrowvert b\Bigr\Arrowvert\ \biggl\arrowvert b\Biggr\Arrowvert
+
+   \left.\bracevert b\right\bracevert\ \bigl\bracevert b\Bigr\bracevert\ \biggl\bracevert b\Biggr\bracevert
+   \quad
+   \left.\vert \frac{b}{a}\right\Vert\ \bigl\vert b\Bigr\Vert\ \biggl\vert b\Biggr\Vert
+   \quad
+   
diff --git a/docutils/docutils/utils/math/__init__.py b/docutils/docutils/utils/math/__init__.py
index 87e608dd7..3e18434b8 100644
--- a/docutils/docutils/utils/math/__init__.py
+++ b/docutils/docutils/utils/math/__init__.py
@@ -25,6 +25,12 @@ It contains various modules for conversion between different math formats
 # helpers for Docutils math support
 # =================================
 
+def toplevel_code(code):
+    """Return string (LaTeX math) `code` with environments stripped out."""
+    chunks = code.split(r'\begin{')
+    return r'\begin{'.join([chunk.split(r'\end{')[-1]
+                            for chunk in chunks])
+
 def pick_math_environment(code, numbered=False):
     """Return the right math environment to display `code`.
 
@@ -35,11 +41,7 @@ def pick_math_environment(code, numbered=False):
     If `numbered` evaluates to ``False``, the "starred" versions are used
     to suppress numbering.
     """
-    # cut out environment content:
-    chunks = code.split(r'\begin{')
-    toplevel_code = ''.join([chunk.split(r'\end{')[-1]
-                             for chunk in chunks])
-    if toplevel_code.find(r'\\') >= 0:
+    if toplevel_code(code).find(r'\\') >= 0:
         env = 'align'
     else:
         env = 'equation'
diff --git a/docutils/docutils/utils/math/latex2mathml.py b/docutils/docutils/utils/math/latex2mathml.py
index eb46d7f05..1f7f69284 100644
--- a/docutils/docutils/utils/math/latex2mathml.py
+++ b/docutils/docutils/utils/math/latex2mathml.py
@@ -29,7 +29,7 @@ import sys
 if sys.version_info >= (3, 0):
     unicode = str  # noqa
 
-from docutils.utils.math import tex2unichar
+from docutils.utils.math import tex2unichar, toplevel_code
 
 
 # Character data
@@ -159,11 +159,10 @@ small_operators = {# mathsize='75%'
 
 # Operators and functions with limits above/below in display formulas
 # and in index position inline (movablelimits="true")
-displaylimits = [operators[name] for name in
-                 ('bigcap', 'bigcup', 'bigodot', 'bigoplus', 'bigotimes',
+displaylimits = ('bigcap', 'bigcup', 'bigodot', 'bigoplus', 'bigotimes',
                   'bigsqcup', 'biguplus', 'bigvee', 'bigwedge',
-                  'coprod', 'prod', 'sum',
-                  'lim', 'max', 'min', 'sup', 'inf')]
+                  'coprod', 'intop', 'ointop', 'prod', 'sum',
+                  'lim', 'max', 'min', 'sup', 'inf')
 # Depending on settings, integrals may also be in this category.
 # (e.g. if "amsmath" is loaded with option "intlimits", see
 #  http://mirror.ctan.org/macros/latex/required/amsmath/amsldoc.pdf)
@@ -171,8 +170,6 @@ displaylimits = [operators[name] for name in
 #                       'oint', 'ointctrclockwise', 'sqint',
 #                       'varointclockwise',))
 
-# >>> print(' '.join(displaylimits))
-# ⋂ ⋃ ⨀ ⨁ ⨂ ⨆ ⨄ ⋁ ⋀ ∐ ∏ ∑ lim max min sup inf
 
 # pre-composed characters for negated symbols
 # see https://www.w3.org/TR/xml-entity-names/#combining
@@ -188,6 +185,10 @@ stretchables = {'backslash':   '\\',
                 'Uparrow':     u'\u21d1', # ⇑ UPWARDS DOUBLE ARROW
                 'Downarrow':   u'\u21d3', # ⇓ DOWNWARDS DOUBLE ARROW
                 'Updownarrow': u'\u21d5', # ⇕ UP DOWN DOUBLE ARROW
+                'lmoustache':  u'\u23b0', # ⎰ UPPER LEFT OR LOWER RIGHT CURLY BRACKET SECTION
+                'rmoustache':  u'\u23b1', # ⎱ UPPER RIGHT OR LOWER LEFT CURLY BRACKET SECTION
+                'arrowvert':   u'\u23d0', # ⏐ VERTICAL LINE EXTENSION
+                'bracevert':   u'\u23aa', # ⎪ CURLY BRACKET EXTENSION
                }
 stretchables.update(tex2unichar.mathfence)
 stretchables.update(tex2unichar.mathopen)
@@ -195,8 +196,7 @@ stretchables.update(tex2unichar.mathclose)
 stretchables.update(math_fences)
 
 # >>> print(' '.join(sorted(set(stretchables.values()))))
-# [ \ ] { | } ‖ ↑ ↓ ↕ ⇑ ⇓ ⇕ ⌈ ⌉ ⌊ ⌋ ⌜ ⌝ ⌞ ⌟ ⟅ ⟆ ⟦ ⟧ ⟨ ⟩ ⟮ ⟯ ⦇ ⦈
-
+# [ \ ] { | } ‖ ↑ ↓ ↕ ⇑ ⇓ ⇕ ⌈ ⌉ ⌊ ⌋ ⌜ ⌝ ⌞ ⌟ ⎪ ⎰ ⎱ ⏐ ⟅ ⟆ ⟦ ⟧ ⟨ ⟩ ⟮ ⟯ ⦇ ⦈
 
 # horizontal space -> <mspace>
 
@@ -216,7 +216,7 @@ spaces = {'qquad':         '2em',       # two \quad
           '!':             '-0.1667em', # negthinspace
          }
 
-# accents -> <mover accent="true">
+# accents -> <mover accent="true"> # TODO: stretchy="false"
 #        TeX        spacing    combining
 accents = {'acute':    u'´',      # u'\u0301',
            'bar':      u'ˉ',      # u'\u0304',
@@ -225,6 +225,7 @@ accents = {'acute':    u'´',      # u'\u0301',
            'dot':      u'˙',      # u'\u0307',
            'ddot':     u'¨',      # u'\u0308',
            'dddot':               u'\u20DB',  # '…' too wide
+           # TODO: ddddot
            'grave':    u'`',      # u'\u0300',
            'hat':      u'ˆ',      # u'\u0302',
            'mathring': u'˚',      # u'\u030A',
@@ -358,6 +359,8 @@ class math(object):
         return self.attributes[key]
     def __setitem__(self, key, item):
         self.attributes[key] = item
+    def get(self, *args, **kwargs):
+        return self.attributes.get(*args, **kwargs)
 
     def full(self):
         """Return boolean indicating whether children may be appended."""
@@ -627,47 +630,103 @@ def tex_number(string):
 def tex_token(string):
     """Return first simple TeX token and remainder of `string`.
 
-    >>> tex_token('{first simple group} returned without brackets')
-    ('first simple group', ' returned without brackets')
     >>> tex_token('\\command{without argument}')
     ('\\command', '{without argument}')
-    >>> tex_token(' first non-white character')
-    ('f', 'irst non-white character')
+    >>> tex_token('or first character')
+    ('o', 'r first character')
 
     """
-    m = re.match(r"""\s*                  # leading whitespace
-                 {(?P<token>(\\}|[^{}]|\\{)*)} # {group} without nested groups
-                 (?P<remainder>.*$)
-                 """, string, re.VERBOSE)
-    if m is None:
-        m = re.match(r"""\s*              # leading whitespace
-                      (?P<token>\\([a-zA-Z]+))\s*   # \cmdname
-                      (?P<remainder>.*$)
-                 """, string, re.VERBOSE)
-    if m is None:
-        m = re.match(r"""\s*              # leading whitespace
-                     (?P<token>.?)        # first character or empty string
-                     (?P<remainder>.*$)
+    m = re.match(r"""((?P<cmd>\\[a-zA-Z]+)\s* # TeX command, skip whitespace
+                      |(?P<chcmd>\\.)          # one-character TeX command
+                      |(?P<ch>.?))            # first character (or empty)
+                     (?P<remainder>.*$)    # remaining part of string
                  """, string, re.VERBOSE)
-
-    return m.group('token'), m.group('remainder')
+    cmd, chcmd, ch, remainder = m.group('cmd', 'chcmd', 'ch', 'remainder')
+    return cmd or chcmd or ch, remainder
 
 # Test:
 #
-# >>> tex_token('{opening bracket of group with {nested group}}')
-# ('{', 'opening bracket of group with {nested group}}')
-# >>> tex_token('{group with \\{escaped\\} brackets}')
-# ('group with \\{escaped\\} brackets', '')
-# >>> tex_token('{group followed by closing bracket}} from outer group')
-# ('group followed by closing bracket', '} from outer group')
-# >>> tex_token(' {skip leading whitespace}')
-# ('skip leading whitespace', '')
-# >>> tex_token('  \\skip{leading whitespace}')
-# ('\\skip', '{leading whitespace}')
+# >>> tex_token('{opening bracket of group}')
+# ('{', 'opening bracket of group}')
 # >>> tex_token('\\skip whitespace after macro name')
 # ('\\skip', 'whitespace after macro name')
+# >>> tex_token('. but not after single char')
+# ('.', ' but not after single char')
 # >>> tex_token('') # empty string.
 # ('', '')
+# >>> tex_token('\{escaped bracket')
+# ('\\{', 'escaped bracket')
+
+def tex_group(string):
+    """Return first TeX group or token and remainder of `string`.
+
+    >>> tex_group('{first group} returned without brackets')
+    ('first group', ' returned without brackets')
+
+    """
+    split_index = 0
+    nest_level = 0   # level of {{nested} groups}
+    escape = False   # the next character is escaped (\)
+
+    if not string.startswith('{'):
+        # special case: there is no group, return first token and remainder
+        return string[:1], string[1:]
+    for c in string:
+        split_index += 1
+        if escape:
+            escape = False
+        elif c == '\\':
+            escape = True
+        elif c == '{':
+            nest_level += 1
+        elif c == '}':
+            nest_level -= 1
+        if nest_level == 0:
+            break
+    else:
+        raise SyntaxError('Group without closing bracket')
+    return string[1:split_index-1], string[split_index:]
+
+
+
+# >>> tex_group('{} empty group')
+# ('', ' empty group')
+# >>> tex_group('{group with {nested} group} ')
+# ('group with {nested} group', ' ')
+# >>> tex_group('{group with {nested group}} at the end')
+# ('group with {nested group}', ' at the end')
+# >>> tex_group('{{group} {with {{complex }nesting}} constructs}')
+# ('{group} {with {{complex }nesting}} constructs', '')
+# >>> tex_group('{group with \\{escaped\\} brackets}')
+# ('group with \\{escaped\\} brackets', '')
+# >>> tex_group('{group followed by closing bracket}} from outer group')
+# ('group followed by closing bracket', '} from outer group')
+# >>> tex_group('No group? Return first character.')
+# ('N', 'o group? Return first character.')
+# >>> tex_group(' {also whitespace}')
+# (' ', '{also whitespace}')
+
+
+def tex_token_or_group(string):
+    """Return first TeX group or token and remainder of `string`.
+
+    >>> tex_token_or_group('\\command{without argument}')
+    ('\\command', '{without argument}')
+    >>> tex_token_or_group('first character')
+    ('f', 'irst character')
+    >>> tex_token_or_group(' also whitespace')
+    (' ', 'also whitespace')
+    >>> tex_token_or_group('{first group} keep rest')
+    ('first group', ' keep rest')
+
+    """
+    arg, remainder = tex_token(string)
+    if arg == '{':
+        arg, remainder = tex_group(string.lstrip())
+    return arg, remainder
+
+# >>> tex_token_or_group('\{no group but left bracket')
+# ('\\{', 'no group but left bracket')
 
 def tex_optarg(string):
     """Return optional argument and remainder.
@@ -797,13 +856,13 @@ def handle_cmd(name, node, string):
     # identifier  ->  <mi>
 
     if name in letters:
+        new_node = mi(letters[name])
         if name in greek_capitals:
             # upright in "TeX style" but MathML sets them italic ("ISO style").
             # CSS styling does not change the font style in Firefox 78.
             # Use 'mathvariant="normal"'?
-            node = node.append(mi(greek_capitals[name], CLASS='capital-greek'))
-        else:
-            node = node.append(mi(letters[name]))
+            new_node['class'] = 'capital-greek'
+        node = node.append(new_node)
         return node, string
 
     if (name in functions):
@@ -812,7 +871,7 @@ def handle_cmd(name, node, string):
         if name == 'operatorname':
             # custom function name, e.g. ``\operatorname{abs}(x)``
             # TODO: \operatorname* -> with limits
-            arg, string = tex_token(string)
+            arg, string = tex_token_or_group(string)
             new_node = mi(arg, mathvariant='normal')
         else:
             new_node = mi(functions[name])
@@ -834,22 +893,22 @@ def handle_cmd(name, node, string):
         return node, string
 
     if name in math_alphabets:
-        arg, remainder = tex_token(string)
-        if arg[0] == '\\':
-            # convert single letters (so the isalpha() test below works).
-            arg = letters.get(arg[1:], arg)
-        if name == 'mathbb':
-            # mathvariant="double-struck" is ignored for Greek letters
-            # (tested in Firefox 78). Use literal Unicode characters.
-            arg = mathbb.get(arg, arg)
         if name == 'boldsymbol':
             attributes = {'style': 'font-weight: bold'}
         else:
             attributes = {'mathvariant': math_alphabets[name]}
         if name == 'mathscr':
             attributes['class'] = 'mathscr'
-
-        # one symbol (single letter, name, or ⅀)
+        # Check for single symbol (letter, name, or ⅀)
+        arg, remainder = tex_token_or_group(string)
+        if arg.startswith('\\'):
+            # convert single letters (so the isalpha() test below works).
+            # TODO: convert all LICRs in a group (\matrm{\mu\Omega})
+            arg = letters.get(arg[1:], arg)
+        if name == 'mathbb':
+            # mathvariant="double-struck" is ignored for Greek letters
+            # (tested in Firefox 78). Use literal Unicode characters.
+            arg = mathbb.get(arg, arg)
         if arg.isalpha() or arg == u'\u2140':
             node = node.append(mi(arg, **attributes))
             return node, remainder
@@ -874,21 +933,26 @@ def handle_cmd(name, node, string):
         return node, string
 
     if name in operators:
-        node = node.append(mo(operators[name]))
+        if name in displaylimits and string and string[0] in ' _^':
+            node = node.append(mo(operators[name], movablelimits = 'true'))
+        else:
+            node = node.append(mo(operators[name]))
         return node, string
 
     if name in delimiter_sizes:
         delimiter_attributes = {}
         size = delimiter_sizes[name]
-        delimiter, string = tex_token(string)
+        delimiter, string = tex_token_or_group(string)
         if delimiter not in '()[]/|.':
             try:
                 delimiter = stretchables[delimiter.lstrip('\\')]
             except KeyError:
-                raise SyntaxError(u'Missing "\\%s" delimiter!' % name)
+                raise SyntaxError(u'Unsupported "\\%s" delimiter "%s"!'
+                                  % (name, delimiter))
         if size:
             delimiter_attributes['maxsize'] = size
             delimiter_attributes['minsize'] = size
+            delimiter_attributes['symmetric'] = 'true'
         if name == 'left' or name.endswith('l'):
             row = mrow()
             node.append(row)
@@ -900,7 +964,7 @@ def handle_cmd(name, node, string):
         return node, string
 
     if name == 'not':
-        arg, string = tex_token(string)
+        arg, string = tex_token_or_group(string)
         try:
             node = node.append(mo(negatables[arg]))
         except KeyError:
@@ -909,7 +973,7 @@ def handle_cmd(name, node, string):
 
     # arbitrary text (usually comments)  ->  <mtext>
     if name in ('text', 'mbox', 'textrm'):
-        arg, string = tex_token(string)
+        arg, string = tex_token_or_group(string)
         parts = arg.split('$') # extract inline math
         for i, part in enumerate(parts):
             if i % 2 == 0: # i is even
@@ -924,8 +988,10 @@ def handle_cmd(name, node, string):
         node = node.append(mspace(width='%s'%spaces[name]))
         return node, string
 
-    if name == 'hspace':
-        arg, string = tex_token(string)
+    if name in ('hspace', 'mspace'):
+        arg, string = tex_group(string)
+        if arg.endswith('mu'):
+            arg = '%sem' % (float(arg[:-2])/18)
         node = node.append(mspace(width='%s'%arg))
         return node, string
 
@@ -1053,7 +1119,7 @@ def handle_cmd(name, node, string):
 
 # >>> handle_cmd('left', math(), '[a\\right]')
 # (mrow(mo('[')), 'a\\right]')
-# >>> handle_cmd('left', math(), '. a)') # emtpy \left
+# >>> handle_cmd('left', math(), '. a)') # empty \left
 # (mrow(), ' a)')
 # >>> handle_cmd('left', math(), '\\uparrow a)') # cmd
 # (mrow(mo('↑')), 'a)')
@@ -1103,7 +1169,7 @@ def handle_script_or_limit(node, c, limits=''):
             new_node = munderover(*child.children, switch=True)
         elif (limits in ('limits', 'displaylimits')
               or limits == ''
-              and getattr(child, 'data', '') in displaylimits):
+              and child.get('movablelimits', None) == 'true'):
             new_node = munder(child)
         else:
             new_node = msub(child)
@@ -1114,7 +1180,7 @@ def handle_script_or_limit(node, c, limits=''):
             new_node = munderover(*child.children)
         elif (limits in ('limits', 'displaylimits')
               or limits == ''
-              and getattr(child, 'data', '') in displaylimits):
+              and child.get('movablelimits', None) == 'true'):
             new_node = mover(child)
         else:
             new_node = msup(child)
@@ -1123,7 +1189,7 @@ def handle_script_or_limit(node, c, limits=''):
 
 
 def begin_environment(node, string):
-    name, string = tex_token(string)
+    name, string = tex_group(string)
     if name in matrices:
         left_delimiter = matrices[name][0]
         attributes = {}
@@ -1137,6 +1203,8 @@ def begin_environment(node, string):
             wrapper = mstyle(scriptlevel=1)
             node.append(wrapper)
             node = wrapper
+        # TODO: aligned, alignedat
+        # take an optional [t], [b] or the default [c]
         entry = mtd()
         node.append(mtable(mtr(entry), **attributes))
         node = entry
@@ -1146,7 +1214,7 @@ def begin_environment(node, string):
 
 
 def end_environment(node, string):
-    name, string = tex_token(string)
+    name, string = tex_group(string)
     if name in matrices:
         node = node.close().close().close() # close: mtd, mdr, mtable
         right_delimiter = matrices[name][1]
@@ -1160,23 +1228,64 @@ def end_environment(node, string):
     return node, string
 
 
+# Return the number of "equation_columns" in `code_lines`. See "alignat"
+# in http://mirror.ctan.org/macros/latex/required/amsmath/amsldoc.pdf
+def tex_equation_columns(rows):
+    tabs = max(row.count('&') - row.count(r'\&') for row in rows)
+    if tabs == 0:
+        return 0
+    return int(tabs/2 + 1)
+
+# >>> tex_equation_columns(['a = b'])
+# 0
+# >>> tex_equation_columns(['a &= b'])
+# 1
+# >>> tex_equation_columns(['a &= b & a \in S'])
+# 2
+# >>> tex_equation_columns(['a &= b & c &= d'])
+# 2
+
+
+# Return dictionary with attributes to style an <mtable> as align environment:
+def align_attributes(rows):
+    atts = {'class': 'alignat',
+            'displaystyle': 'true'}
+    tabs = max(row.count('&') - row.count(r'\&') for row in rows)
+    if tabs:
+        aligns = ['right', 'left'] * tabs
+        spacing = ['0', '2em'] * tabs
+        atts['columnalign'] = ' '.join(aligns[:tabs+1])
+        atts['columnspacing'] = ' '.join(spacing[:tabs])
+    return atts
+
+# >>> align_attributes(['a = b'])
+# {'class': 'alignat', 'displaystyle': 'true'}
+# >>> align_attributes(['a &= b'])
+# {'class': 'alignat', 'displaystyle': 'true', 'columnalign': 'right left', 'columnspacing': '0'}
+# >>> align_attributes(['a &= b & a \in S'])
+# {'class': 'alignat', 'displaystyle': 'true', 'columnalign': 'right left right', 'columnspacing': '0 2em'}
+# >>> align_attributes(['a &= b & c &= d'])
+# {'class': 'alignat', 'displaystyle': 'true', 'columnalign': 'right left right left', 'columnspacing': '0 2em 0'}
+
+
 def tex2mathml(tex_math, inline=True):
     """Return string with MathML code corresponding to `tex_math`.
 
     Set `inline` to False for displayed math.
     """
     # Set up tree
-    tree = math(xmlns='http://www.w3.org/1998/Math/MathML')
-    if inline:
-        node = tree
-    else:
-        # block: emulate align* environment with a math table
-        tree['display'] = 'block'
-        node = mtd()
-        tree.append(mtable(mtr(node), displaystyle='true', CLASS='align'))
-
+    math_tree = math(xmlns='http://www.w3.org/1998/Math/MathML')
+    node = math_tree
+    if not inline:
+        math_tree['display'] = 'block'
+        rows = toplevel_code(tex_math).split(r'\\')
+        if len(rows) > 1:
+            # emulate align* environment with a math table
+            node = mtd()
+            math_tree.append(mtable(mtr(node),
+                                    **align_attributes(rows)))
     parse_latex_math(node, tex_math)
-    return tree.toprettyxml()
+    return math_tree.toprettyxml()
 
 # >>> print(tex2mathml('3'))
 # <math xmlns="http://www.w3.org/1998/Math/MathML">
@@ -1184,26 +1293,57 @@ def tex2mathml(tex_math, inline=True):
 # </math>
 # >>> print(tex2mathml('3', inline=False))
 # <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-#   <mtable class="align" displaystyle="true">
+#   <mn>3</mn>
+# </math>
+# >>> print(tex2mathml(r'a & b \\ c & d', inline=False))
+# <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
+#   <mtable class="alignat" columnalign="right left" columnspacing="0" displaystyle="true">
+#     <mtr>
+#       <mtd>
+#         <mi>a</mi>
+#       </mtd>
+#       <mtd>
+#         <mi>b</mi>
+#       </mtd>
+#     </mtr>
+#     <mtr>
+#       <mtd>
+#         <mi>c</mi>
+#       </mtd>
+#       <mtd>
+#         <mi>d</mi>
+#       </mtd>
+#     </mtr>
+#   </mtable>
+# </math>
+# >>> print(tex2mathml(r'a \\ b', inline=False))
+# <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
+#   <mtable class="alignat" displaystyle="true">
 #     <mtr>
 #       <mtd>
-#         <mn>3</mn>
+#         <mi>a</mi>
+#       </mtd>
+#     </mtr>
+#     <mtr>
+#       <mtd>
+#         <mi>b</mi>
 #       </mtd>
 #     </mtr>
 #   </mtable>
 # </math>
 
+
 # TODO: look up more symbols from tr25, e.g.
-#
-#
+# 
+# 
 # Table 2.8 Using Vertical Line or Solidus Overlay
 #   some of the negated forms of mathematical relations that can only be
 #   encoded by using either U+0338 COMBINING LONG SOLIDUS OVERLAY or U+20D2
 #   COMBINING LONG VERTICAL LINE OVERLAY . (For issues with using 0338 in
 #   MathML, see Section 3.2.7, Combining Marks.
-#
+# 
 # Table 2.9 Variants of Mathematical Symbols using VS1?
-#
+# 
 # Sequence      Description
 # 0030 + VS1    DIGIT ZERO - short diagonal stroke form
 # 2205 + VS1    EMPTY SET - zero with long diagonal stroke overlay form
@@ -1230,3 +1370,4 @@ def tex2mathml(tex_math, inline=True):
 # 2AAD + VS1    LARGER THAN OR slanted EQUAL
 # 2ACB + VS1    SUBSET OF ABOVE NOT EQUAL TO - variant with stroke through bottom members
 # 2ACC + VS1    SUPERSET OF ABOVE NOT EQUAL TO - variant with stroke through bottom members
+
diff --git a/docutils/docutils/utils/math/tex2unichar.py b/docutils/docutils/utils/math/tex2unichar.py
index 3630793e5..c9c10405d 100644
--- a/docutils/docutils/utils/math/tex2unichar.py
+++ b/docutils/docutils/utils/math/tex2unichar.py
@@ -227,9 +227,11 @@ mathop = {
     'iiint': u'\u222d', # ∭ TRIPLE INTEGRAL
     'iint': u'\u222c', # ∬ DOUBLE INTEGRAL
     'int': u'\u222b', # ∫ INTEGRAL
+    'intop': u'\u222b', # ∫ INTEGRAL
     'oiint': u'\u222f', # ∯ SURFACE INTEGRAL
     'oint': u'\u222e', # ∮ CONTOUR INTEGRAL
     'ointctrclockwise': u'\u2233', # ∳ ANTICLOCKWISE CONTOUR INTEGRAL
+    'ointop': u'\u222e', # ∮ CONTOUR INTEGRAL
     'prod': u'\u220f', # ∏ N-ARY PRODUCT
     'sqint': u'\u2a16', # ⨖ QUATERNION INTEGRAL OPERATOR
     'sum': u'\u2211', # ∑ N-ARY SUMMATION
@@ -325,8 +327,8 @@ mathord = {
     'dasharrow': u'\u21e2', # ⇢ RIGHTWARDS DASHED ARROW
     'dashleftarrow': u'\u21e0', # ⇠ LEFTWARDS DASHED ARROW
     'dashrightarrow': u'\u21e2', # ⇢ RIGHTWARDS DASHED ARROW
-    'diagdown': u'\u27cd', # ⟍ 
-    'diagup': u'\u27cb', # ⟋ 
+    'diagdown': u'\u27cd', # ⟍
+    'diagup': u'\u27cb', # ⟋
     'diameter': u'\u2300', # ⌀ DIAMETER SIGN
     'diamondsuit': u'\u2662', # ♢ WHITE DIAMOND SUIT
     'earth': u'\u2641', # ♁ EARTH
diff --git a/docutils/test/functional/expected/math_output_mathml.html b/docutils/test/functional/expected/math_output_mathml.html
index aebcc3b35..37191201f 100644
--- a/docutils/test/functional/expected/math_output_mathml.html
+++ b/docutils/test/functional/expected/math_output_mathml.html
@@ -44,57 +44,45 @@ role specificator, <math xmlns="http://www.w3.org/1998/Math/MathML">
 <cite>math</cite> directive:</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mi>f</mi>
-        <mo stretchy="false">(</mo>
-        <mi>ϵ</mi>
-        <mo stretchy="false">)</mo>
-        <mo>=</mo>
+  <mi>f</mi>
+  <mo stretchy="false">(</mo>
+  <mi>ϵ</mi>
+  <mo stretchy="false">)</mo>
+  <mo>=</mo>
+  <mfrac>
+    <mn>1</mn>
+    <mrow>
+      <mn>1</mn>
+      <mo>+</mo>
+      <mi>exp</mi>
+      <mo>&ApplyFunction;</mo>
+      <mrow>
+        <mo>(</mo>
         <mfrac>
-          <mn>1</mn>
+          <mi>ε</mi>
           <mrow>
-            <mn>1</mn>
-            <mo>+</mo>
-            <mi>exp</mi>
-            <mo>&ApplyFunction;</mo>
-            <mrow>
-              <mo>(</mo>
-              <mfrac>
-                <mi>ε</mi>
-                <mrow>
-                  <msub>
-                    <mi>k</mi>
-                    <mtext>B</mtext>
-                  </msub>
-                  <mi>T</mi>
-                </mrow>
-              </mfrac>
-              <mo>)</mo>
-            </mrow>
+            <msub>
+              <mi>k</mi>
+              <mtext>B</mtext>
+            </msub>
+            <mi>T</mi>
           </mrow>
         </mfrac>
-      </mtd>
-    </mtr>
-  </mtable>
+        <mo>)</mo>
+      </mrow>
+    </mrow>
+  </mfrac>
 </math>
 </div>
 <p>Content may start on the first line of the directive, e.g.</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mi>N</mi>
-        <mo>=</mo>
-        <mfrac>
-          <mtext>number of apples</mtext>
-          <mn>7</mn>
-        </mfrac>
-      </mtd>
-    </mtr>
-  </mtable>
+  <mi>N</mi>
+  <mo>=</mo>
+  <mfrac>
+    <mtext>number of apples</mtext>
+    <mn>7</mn>
+  </mfrac>
 </math>
 </div>
 <p>Equations can be labeled with a reference name using the <span class="docutils literal">:name:</span> option.
@@ -102,36 +90,30 @@ See <a class="reference internal" href="#eq-m">eq:M</a> and <a class="reference
 <p>The determinant of the matrix</p>
 <div id="eq-m">
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mi mathvariant="bold">M</mi>
-        <mo>=</mo>
-        <mrow>
-          <mo>(</mo>
-          <mtable>
-            <mtr>
-              <mtd>
-                <mi>a</mi>
-              </mtd>
-              <mtd>
-                <mi>b</mi>
-              </mtd>
-            </mtr>
-            <mtr>
-              <mtd>
-                <mi>c</mi>
-              </mtd>
-              <mtd>
-                <mi>d</mi>
-              </mtd>
-            </mtr>
-          </mtable>
-          <mo>)</mo>
-        </mrow>
-      </mtd>
-    </mtr>
-  </mtable>
+  <mi mathvariant="bold">M</mi>
+  <mo>=</mo>
+  <mrow>
+    <mo>(</mo>
+    <mtable>
+      <mtr>
+        <mtd>
+          <mi>a</mi>
+        </mtd>
+        <mtd>
+          <mi>b</mi>
+        </mtd>
+      </mtr>
+      <mtr>
+        <mtd>
+          <mi>c</mi>
+        </mtd>
+        <mtd>
+          <mi>d</mi>
+        </mtd>
+      </mtr>
+    </mtable>
+    <mo>)</mo>
+  </mrow>
 </math>
 </div>
 <p>is <math xmlns="http://www.w3.org/1998/Math/MathML">
@@ -149,64 +131,52 @@ See <a class="reference internal" href="#eq-m">eq:M</a> and <a class="reference
 For example, the following sum and integral with limits:</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <msubsup>
-          <mo>∫</mo>
-          <mn>0</mn>
-          <mn>1</mn>
-        </msubsup>
-        <msup>
-          <mi>x</mi>
-          <mi>n</mi>
-        </msup>
-        <mi>d</mi>
-        <mi>x</mi>
-        <mo>=</mo>
-        <mfrac>
-          <mn>1</mn>
-          <mrow>
-            <mi>n</mi>
-            <mo>+</mo>
-            <mn>1</mn>
-          </mrow>
-        </mfrac>
-      </mtd>
-    </mtr>
-  </mtable>
+  <msubsup>
+    <mo>∫</mo>
+    <mn>0</mn>
+    <mn>1</mn>
+  </msubsup>
+  <msup>
+    <mi>x</mi>
+    <mi>n</mi>
+  </msup>
+  <mi>d</mi>
+  <mi>x</mi>
+  <mo>=</mo>
+  <mfrac>
+    <mn>1</mn>
+    <mrow>
+      <mi>n</mi>
+      <mo>+</mo>
+      <mn>1</mn>
+    </mrow>
+  </mfrac>
 </math>
 </div>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <munderover>
-          <mo movablelimits="true">∑</mo>
-          <mrow>
-            <mi>n</mi>
-            <mo>=</mo>
-            <mn>1</mn>
-          </mrow>
-          <mi>m</mi>
-        </munderover>
-        <mi>n</mi>
-        <mo>=</mo>
-        <mfrac>
-          <mrow>
-            <mi>m</mi>
-            <mo stretchy="false">(</mo>
-            <mi>m</mi>
-            <mo>+</mo>
-            <mn>1</mn>
-            <mo stretchy="false">)</mo>
-          </mrow>
-          <mn>2</mn>
-        </mfrac>
-      </mtd>
-    </mtr>
-  </mtable>
+  <munderover>
+    <mo movablelimits="true">∑</mo>
+    <mrow>
+      <mi>n</mi>
+      <mo>=</mo>
+      <mn>1</mn>
+    </mrow>
+    <mi>m</mi>
+  </munderover>
+  <mi>n</mi>
+  <mo>=</mo>
+  <mfrac>
+    <mrow>
+      <mi>m</mi>
+      <mo stretchy="false">(</mo>
+      <mi>m</mi>
+      <mo>+</mo>
+      <mn>1</mn>
+      <mo stretchy="false">)</mo>
+    </mrow>
+    <mn>2</mn>
+  </mfrac>
 </math>
 </div>
 <p>LaTeX-supported Unicode math symbols can be used in math roles and
@@ -214,29 +184,23 @@ directives:</p>
 <p>The Schrödinger equation</p>
 <div id="eq-schrodinger">
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mi>i</mi>
-        <mi>ℏ</mi>
-        <mfrac>
-          <mo>∂</mo>
-          <mrow>
-            <mo>∂</mo>
-            <mi>t</mi>
-          </mrow>
-        </mfrac>
-        <mi class="capital-greek">Ψ</mi>
-        <mo>=</mo>
-        <mover accent="true">
-          <mi>H</mi>
-          <mo>ˆ</mo>
-        </mover>
-        <mi class="capital-greek">Ψ</mi>
-        <mo>,</mo>
-      </mtd>
-    </mtr>
-  </mtable>
+  <mi>i</mi>
+  <mi>ℏ</mi>
+  <mfrac>
+    <mo>∂</mo>
+    <mrow>
+      <mo>∂</mo>
+      <mi>t</mi>
+    </mrow>
+  </mfrac>
+  <mi class="capital-greek">Ψ</mi>
+  <mo>=</mo>
+  <mover accent="true">
+    <mi>H</mi>
+    <mo>ˆ</mo>
+  </mover>
+  <mi class="capital-greek">Ψ</mi>
+  <mo>,</mo>
 </math>
 </div>
 <p>with the <em>wave function</em> <math xmlns="http://www.w3.org/1998/Math/MathML">
@@ -337,101 +301,95 @@ physical system changes in time.</p>
 <p>Modulation Transfer Function:</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mtext>MTF</mtext>
-        <mo>=</mo>
-        <mrow>
-          <mo>|</mo>
-          <mfrac>
-            <mrow>
-              <mi mathvariant="script">F</mi>
-              <mo>{</mo>
-              <mi>s</mi>
-              <mo stretchy="false">(</mo>
-              <mi>x</mi>
-              <mo stretchy="false">)</mo>
-              <mo>}</mo>
-            </mrow>
-            <mrow>
-              <mi mathvariant="script">F</mi>
-              <mo>{</mo>
-              <mi>s</mi>
-              <mo stretchy="false">(</mo>
-              <mi>x</mi>
-              <mo stretchy="false">)</mo>
-              <mo>}</mo>
-              <msub>
-                <mo stretchy="false">|</mo>
-                <mrow>
-                  <msub>
-                    <mi>ω</mi>
-                    <mi>x</mi>
-                  </msub>
-                  <mo>=</mo>
-                  <mn>0</mn>
-                </mrow>
-              </msub>
-            </mrow>
-          </mfrac>
-          <mo>|</mo>
-        </mrow>
-        <mo>=</mo>
-        <mi mathvariant="normal">abs</mi>
-        <mrow>
-          <mo>(</mo>
-          <mfrac>
-            <mrow>
-              <msubsup>
-                <mo>∫</mo>
-                <mrow>
-                  <mo>−</mo>
-                  <mo>∞</mo>
-                </mrow>
-                <mo>∞</mo>
-              </msubsup>
-              <mi>s</mi>
-              <mo stretchy="false">(</mo>
-              <mi>x</mi>
-              <mo stretchy="false">)</mo>
-              <msup>
-                <mi mathvariant="normal">e</mi>
-                <mrow>
-                  <mi mathvariant="normal">i</mi>
-                  <msub>
-                    <mi>ω</mi>
-                    <mi>x</mi>
-                  </msub>
-                  <mi>x</mi>
-                </mrow>
-              </msup>
-              <mi mathvariant="normal">d</mi>
-              <mi>x</mi>
-            </mrow>
-            <mrow>
-              <msubsup>
-                <mo>∫</mo>
-                <mrow>
-                  <mo>−</mo>
-                  <mo>∞</mo>
-                </mrow>
-                <mo>∞</mo>
-              </msubsup>
-              <mi>s</mi>
-              <mo stretchy="false">(</mo>
+  <mtext>MTF</mtext>
+  <mo>=</mo>
+  <mrow>
+    <mo>|</mo>
+    <mfrac>
+      <mrow>
+        <mi mathvariant="script">F</mi>
+        <mo>{</mo>
+        <mi>s</mi>
+        <mo stretchy="false">(</mo>
+        <mi>x</mi>
+        <mo stretchy="false">)</mo>
+        <mo>}</mo>
+      </mrow>
+      <mrow>
+        <mi mathvariant="script">F</mi>
+        <mo>{</mo>
+        <mi>s</mi>
+        <mo stretchy="false">(</mo>
+        <mi>x</mi>
+        <mo stretchy="false">)</mo>
+        <mo>}</mo>
+        <msub>
+          <mo stretchy="false">|</mo>
+          <mrow>
+            <msub>
+              <mi>ω</mi>
               <mi>x</mi>
-              <mo stretchy="false">)</mo>
-              <mi mathvariant="normal">d</mi>
+            </msub>
+            <mo>=</mo>
+            <mn>0</mn>
+          </mrow>
+        </msub>
+      </mrow>
+    </mfrac>
+    <mo>|</mo>
+  </mrow>
+  <mo>=</mo>
+  <mi mathvariant="normal">abs</mi>
+  <mrow>
+    <mo>(</mo>
+    <mfrac>
+      <mrow>
+        <msubsup>
+          <mo>∫</mo>
+          <mrow>
+            <mo>−</mo>
+            <mo>∞</mo>
+          </mrow>
+          <mo>∞</mo>
+        </msubsup>
+        <mi>s</mi>
+        <mo stretchy="false">(</mo>
+        <mi>x</mi>
+        <mo stretchy="false">)</mo>
+        <msup>
+          <mi mathvariant="normal">e</mi>
+          <mrow>
+            <mi mathvariant="normal">i</mi>
+            <msub>
+              <mi>ω</mi>
               <mi>x</mi>
-            </mrow>
-          </mfrac>
-          <mo>)</mo>
-        </mrow>
-        <mo>.</mo>
-      </mtd>
-    </mtr>
-  </mtable>
+            </msub>
+            <mi>x</mi>
+          </mrow>
+        </msup>
+        <mi mathvariant="normal">d</mi>
+        <mi>x</mi>
+      </mrow>
+      <mrow>
+        <msubsup>
+          <mo>∫</mo>
+          <mrow>
+            <mo>−</mo>
+            <mo>∞</mo>
+          </mrow>
+          <mo>∞</mo>
+        </msubsup>
+        <mi>s</mi>
+        <mo stretchy="false">(</mo>
+        <mi>x</mi>
+        <mo stretchy="false">)</mo>
+        <mi mathvariant="normal">d</mi>
+        <mi>x</mi>
+      </mrow>
+    </mfrac>
+    <mo>)</mo>
+  </mrow>
+  <mo>.</mo>
 </math>
 </div>
 <p>Math split over two lines: If a double backslash is detected outside a
@@ -439,7 +397,7 @@ physical system changes in time.</p>
 <span class="docutils literal">align</span> environment:</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
+  <mtable class="alignat" columnalign="right left" columnspacing="0" displaystyle="true">
     <mtr>
       <mtd>
         <msub>
@@ -508,43 +466,37 @@ physical system changes in time.</p>
 <p>Cases with the <a class="reference external" href="ftp://ftp.ams.org/ams/doc/amsmath/short-math-guide.pdf">AMSmath</a> <span class="docutils literal">cases</span> environment:</p>
 <div>
 <math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
-  <mtable class="align" displaystyle="true">
-    <mtr>
-      <mtd>
-        <mi mathvariant="normal">sgn</mi>
-        <mo stretchy="false">(</mo>
-        <mi>x</mi>
-        <mo stretchy="false">)</mo>
-        <mo>=</mo>
-        <mrow>
-          <mo>{</mo>
-          <mtable>
-            <mtr>
-              <mtd>
-                <mo>−</mo>
-                <mn>1</mn>
-              </mtd>
-              <mtd>
-                <mi>x</mi>
-                <mo>&lt;</mo>
-                <mn>0</mn>
-              </mtd>
-            </mtr>
-            <mtr>
-              <mtd>
-                <mn>1</mn>
-              </mtd>
-              <mtd>
-                <mi>x</mi>
-                <mo>&gt;</mo>
-                <mn>0</mn>
-              </mtd>
-            </mtr>
-          </mtable>
-        </mrow>
-      </mtd>
-    </mtr>
-  </mtable>
+  <mi mathvariant="normal">sgn</mi>
+  <mo stretchy="false">(</mo>
+  <mi>x</mi>
+  <mo stretchy="false">)</mo>
+  <mo>=</mo>
+  <mrow>
+    <mo>{</mo>
+    <mtable>
+      <mtr>
+        <mtd>
+          <mo>−</mo>
+          <mn>1</mn>
+        </mtd>
+        <mtd>
+          <mi>x</mi>
+          <mo>&lt;</mo>
+          <mn>0</mn>
+        </mtd>
+      </mtr>
+      <mtr>
+        <mtd>
+          <mn>1</mn>
+        </mtd>
+        <mtd>
+          <mi>x</mi>
+          <mo>&gt;</mo>
+          <mn>0</mn>
+        </mtd>
+      </mtr>
+    </mtable>
+  </mrow>
 </math>
 </div>
 </main>