--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/env/lib/python3.7/site-packages/docutils/utils/math/latex2mathml.py	Sat May 02 07:14:21 2020 -0400
@@ -0,0 +1,568 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# :Id: $Id: latex2mathml.py 8366 2019-08-27 12:09:19Z milde $
+# :Copyright: © 2010 Günter Milde.
+#             Based on rst2mathml.py from the latex_math sandbox project
+#             © 2005 Jens Jørgen Mortensen
+# :License: Released under the terms of the `2-Clause BSD license`_, in short:
+#
+#    Copying and distribution of this file, with or without modification,
+#    are permitted in any medium without royalty provided the copyright
+#    notice and this notice are preserved.
+#    This file is offered as-is, without any warranty.
+#
+# .. _2-Clause BSD license: http://www.spdx.org/licenses/BSD-2-Clause
+
+
+"""Convert LaTex math code into presentational MathML"""
+
+# Based on the `latex_math` sandbox project by Jens Jørgen Mortensen
+
+import docutils.utils.math.tex2unichar as tex2unichar
+
+#        TeX      spacing    combining
+over = {'acute':    u'\u00B4', # u'\u0301',
+        'bar':      u'\u00AF', # u'\u0304',
+        'breve':    u'\u02D8', # u'\u0306',
+        'check':    u'\u02C7', # u'\u030C',
+        'dot':      u'\u02D9', # u'\u0307',
+        'ddot':     u'\u00A8', # u'\u0308',
+        'dddot':               u'\u20DB',
+        'grave':    u'`',      # u'\u0300',
+        'hat':      u'^',      # u'\u0302',
+        'mathring': u'\u02DA', # u'\u030A',
+        'overleftrightarrow':  u'\u20e1',
+        # 'overline':        # u'\u0305',
+        'tilde':    u'\u02DC', # u'\u0303',
+        'vec':               u'\u20D7'}
+
+Greek = { # Capital Greek letters: (upright in TeX style)
+    'Phi':u'\u03a6', 'Xi':u'\u039e', 'Sigma':u'\u03a3',
+    'Psi':u'\u03a8', 'Delta':u'\u0394', 'Theta':u'\u0398',
+    'Upsilon':u'\u03d2', 'Pi':u'\u03a0', 'Omega':u'\u03a9',
+    'Gamma':u'\u0393', 'Lambda':u'\u039b'}
+
+letters = tex2unichar.mathalpha
+
+special = tex2unichar.mathbin         # Binary symbols
+special.update(tex2unichar.mathrel)   # Relation symbols, arrow symbols
+special.update(tex2unichar.mathord)   # Miscellaneous symbols
+special.update(tex2unichar.mathop)    # Variable-sized symbols
+special.update(tex2unichar.mathopen)  # Braces
+special.update(tex2unichar.mathclose) # Braces
+special.update(tex2unichar.mathfence)
+
+sumintprod = ''.join([special[symbol] for symbol in
+                      ['sum', 'int', 'oint', 'prod']])
+
+functions = ['arccos', 'arcsin', 'arctan', 'arg', 'cos',  'cosh',
+             'cot',    'coth',   'csc',    'deg', 'det',  'dim',
+             'exp',    'gcd',    'hom',    'inf', 'ker',  'lg',
+             'lim',    'liminf', 'limsup', 'ln',  'log',  'max',
+             'min',    'Pr',     'sec',    'sin', 'sinh', 'sup',
+             'tan',    'tanh',
+             'injlim',  'varinjlim', 'varlimsup',
+             'projlim', 'varliminf', 'varprojlim']
+
+
+mathbb = {
+          'A': u'\U0001D538',
+          'B': u'\U0001D539',
+          'C': u'\u2102',
+          'D': u'\U0001D53B',
+          'E': u'\U0001D53C',
+          'F': u'\U0001D53D',
+          'G': u'\U0001D53E',
+          'H': u'\u210D',
+          'I': u'\U0001D540',
+          'J': u'\U0001D541',
+          'K': u'\U0001D542',
+          'L': u'\U0001D543',
+          'M': u'\U0001D544',
+          'N': u'\u2115',
+          'O': u'\U0001D546',
+          'P': u'\u2119',
+          'Q': u'\u211A',
+          'R': u'\u211D',
+          'S': u'\U0001D54A',
+          'T': u'\U0001D54B',
+          'U': u'\U0001D54C',
+          'V': u'\U0001D54D',
+          'W': u'\U0001D54E',
+          'X': u'\U0001D54F',
+          'Y': u'\U0001D550',
+          'Z': u'\u2124',
+         }
+
+mathscr = {
+           'A': u'\U0001D49C',
+           'B': u'\u212C',     # bernoulli function
+           'C': u'\U0001D49E',
+           'D': u'\U0001D49F',
+           'E': u'\u2130',
+           'F': u'\u2131',
+           'G': u'\U0001D4A2',
+           'H': u'\u210B',     # hamiltonian
+           'I': u'\u2110',
+           'J': u'\U0001D4A5',
+           'K': u'\U0001D4A6',
+           'L': u'\u2112',     # lagrangian
+           'M': u'\u2133',     # physics m-matrix
+           'N': u'\U0001D4A9',
+           'O': u'\U0001D4AA',
+           'P': u'\U0001D4AB',
+           'Q': u'\U0001D4AC',
+           'R': u'\u211B',
+           'S': u'\U0001D4AE',
+           'T': u'\U0001D4AF',
+           'U': u'\U0001D4B0',
+           'V': u'\U0001D4B1',
+           'W': u'\U0001D4B2',
+           'X': u'\U0001D4B3',
+           'Y': u'\U0001D4B4',
+           'Z': u'\U0001D4B5',
+           'a': u'\U0001D4B6',
+           'b': u'\U0001D4B7',
+           'c': u'\U0001D4B8',
+           'd': u'\U0001D4B9',
+           'e': u'\u212F',
+           'f': u'\U0001D4BB',
+           'g': u'\u210A',
+           'h': u'\U0001D4BD',
+           'i': u'\U0001D4BE',
+           'j': u'\U0001D4BF',
+           'k': u'\U0001D4C0',
+           'l': u'\U0001D4C1',
+           'm': u'\U0001D4C2',
+           'n': u'\U0001D4C3',
+           'o': u'\u2134',     # order of
+           'p': u'\U0001D4C5',
+           'q': u'\U0001D4C6',
+           'r': u'\U0001D4C7',
+           's': u'\U0001D4C8',
+           't': u'\U0001D4C9',
+           'u': u'\U0001D4CA',
+           'v': u'\U0001D4CB',
+           'w': u'\U0001D4CC',
+           'x': u'\U0001D4CD',
+           'y': u'\U0001D4CE',
+           'z': u'\U0001D4CF',
+          }
+
+negatables = {'=': u'\u2260',
+              r'\in': u'\u2209',
+              r'\equiv': u'\u2262'}
+
+# LaTeX to MathML translation stuff:
+class math(object):
+    """Base class for MathML elements."""
+
+    nchildren = 1000000
+    """Required number of children"""
+
+    def __init__(self, children=None, inline=None):
+        """math([children]) -> MathML element
+
+        children can be one child or a list of children."""
+
+        self.children = []
+        if children is not None:
+            if isinstance(children, list):
+                for child in children:
+                    self.append(child)
+            else:
+                # Only one child:
+                self.append(children)
+
+        if inline is not None:
+            self.inline = inline
+
+    def __repr__(self):
+        if hasattr(self, 'children'):
+            return self.__class__.__name__ + '(%s)' % \
+                   ','.join([repr(child) for child in self.children])
+        else:
+            return self.__class__.__name__
+
+    def full(self):
+        """Room for more children?"""
+
+        return len(self.children) >= self.nchildren
+
+    def append(self, child):
+        """append(child) -> element
+
+        Appends child and returns self if self is not full or first
+        non-full parent."""
+
+        assert not self.full()
+        self.children.append(child)
+        child.parent = self
+        node = self
+        while node.full():
+            node = node.parent
+        return node
+
+    def delete_child(self):
+        """delete_child() -> child
+
+        Delete last child and return it."""
+
+        child = self.children[-1]
+        del self.children[-1]
+        return child
+
+    def close(self):
+        """close() -> parent
+
+        Close element and return first non-full element."""
+
+        parent = self.parent
+        while parent.full():
+            parent = parent.parent
+        return parent
+
+    def xml(self):
+        """xml() -> xml-string"""
+
+        return self.xml_start() + self.xml_body() + self.xml_end()
+
+    def xml_start(self):
+        if not hasattr(self, 'inline'):
+            return ['<%s>' % self.__class__.__name__]
+        xmlns = 'http://www.w3.org/1998/Math/MathML'
+        if self.inline:
+            return ['<math xmlns="%s">' % xmlns]
+        else:
+            return ['<math xmlns="%s" mode="display">' % xmlns]
+
+    def xml_end(self):
+        return ['</%s>' % self.__class__.__name__]
+
+    def xml_body(self):
+        xml = []
+        for child in self.children:
+            xml.extend(child.xml())
+        return xml
+
+class mrow(math):
+    def xml_start(self):
+        return ['\n<%s>' % self.__class__.__name__]
+
+class mtable(math):
+    def xml_start(self):
+        return ['\n<%s>' % self.__class__.__name__]
+
+class mtr(mrow): pass
+class mtd(mrow): pass
+
+class mx(math):
+    """Base class for mo, mi, and mn"""
+
+    nchildren = 0
+    def __init__(self, data):
+        self.data = data
+
+    def xml_body(self):
+        return [self.data]
+
+class mo(mx):
+    translation = {'<': '&lt;', '>': '&gt;'}
+    def xml_body(self):
+        return [self.translation.get(self.data, self.data)]
+
+class mi(mx): pass
+class mn(mx): pass
+
+class msub(math):
+    nchildren = 2
+
+class msup(math):
+    nchildren = 2
+
+class msqrt(math):
+    nchildren = 1
+
+class mroot(math):
+    nchildren = 2
+
+class mfrac(math):
+    nchildren = 2
+
+class msubsup(math):
+    nchildren = 3
+    def __init__(self, children=None, reversed=False):
+        self.reversed = reversed
+        math.__init__(self, children)
+
+    def xml(self):
+        if self.reversed:
+##            self.children[1:3] = self.children[2:0:-1]
+            self.children[1:3] = [self.children[2], self.children[1]]
+            self.reversed = False
+        return math.xml(self)
+
+class mfenced(math):
+    translation = {'\\{': '{', '\\langle': u'\u2329',
+                   '\\}': '}', '\\rangle': u'\u232A',
+                   '.': ''}
+    def __init__(self, par):
+        self.openpar = par
+        math.__init__(self)
+
+    def xml_start(self):
+        open = self.translation.get(self.openpar, self.openpar)
+        close = self.translation.get(self.closepar, self.closepar)
+        return ['<mfenced open="%s" close="%s">' % (open, close)]
+
+class mspace(math):
+    nchildren = 0
+
+class mstyle(math):
+    def __init__(self, children=None, nchildren=None, **kwargs):
+        if nchildren is not None:
+            self.nchildren = nchildren
+        math.__init__(self, children)
+        self.attrs = kwargs
+
+    def xml_start(self):
+        return ['<mstyle '] + ['%s="%s"' % item
+                               for item in self.attrs.items()] + ['>']
+
+class mover(math):
+    nchildren = 2
+    def __init__(self, children=None, reversed=False):
+        self.reversed = reversed
+        math.__init__(self, children)
+
+    def xml(self):
+        if self.reversed:
+            self.children.reverse()
+            self.reversed = False
+        return math.xml(self)
+
+class munder(math):
+    nchildren = 2
+
+class munderover(math):
+    nchildren = 3
+    def __init__(self, children=None):
+        math.__init__(self, children)
+
+class mtext(math):
+    nchildren = 0
+    def __init__(self, text):
+        self.text = text
+
+    def xml_body(self):
+        return [self.text]
+
+def parse_latex_math(string, inline=True):
+    """parse_latex_math(string [,inline]) -> MathML-tree
+
+    Returns a MathML-tree parsed from string.  inline=True is for
+    inline math and inline=False is for displayed math.
+
+    tree is the whole tree and node is the current element."""
+
+    # Normalize white-space:
+    string = ' '.join(string.split())
+
+    if inline:
+        node = mrow()
+        tree = math(node, inline=True)
+    else:
+        node = mtd()
+        tree = math(mtable(mtr(node)), inline=False)
+
+    while len(string) > 0:
+        n = len(string)
+        c = string[0]
+        skip = 1  # number of characters consumed
+        if n > 1:
+            c2 = string[1]
+        else:
+            c2 = ''
+        if c == ' ':
+            pass
+        elif c == '\\':
+            if c2 in '{}':
+                node = node.append(mo(c2))
+                skip = 2
+            elif c2 == ' ':
+                node = node.append(mspace())
+                skip = 2
+            elif c2 == ',': # TODO: small space
+                node = node.append(mspace())
+                skip = 2
+            elif c2.isalpha():
+                # We have a LaTeX-name:
+                i = 2
+                while i < n and string[i].isalpha():
+                    i += 1
+                name = string[1:i]
+                node, skip = handle_keyword(name, node, string[i:])
+                skip += i
+            elif c2 == '\\':
+                # End of a row:
+                entry = mtd()
+                row = mtr(entry)
+                node.close().close().append(row)
+                node = entry
+                skip = 2
+            else:
+                raise SyntaxError(u'Syntax error: "%s%s"' % (c, c2))
+        elif c.isalpha():
+            node = node.append(mi(c))
+        elif c.isdigit():
+            node = node.append(mn(c))
+        elif c in "+-*/=()[]|<>,.!?':;@":
+            node = node.append(mo(c))
+        elif c == '_':
+            child = node.delete_child()
+            if isinstance(child, msup):
+                sub = msubsup(child.children, reversed=True)
+            elif isinstance(child, mo) and child.data in sumintprod:
+                sub = munder(child)
+            else:
+                sub = msub(child)
+            node.append(sub)
+            node = sub
+        elif c == '^':
+            child = node.delete_child()
+            if isinstance(child, msub):
+                sup = msubsup(child.children)
+            elif isinstance(child, mo) and child.data in sumintprod:
+                sup = mover(child)
+            elif (isinstance(child, munder) and
+                  child.children[0].data in sumintprod):
+                sup = munderover(child.children)
+            else:
+                sup = msup(child)
+            node.append(sup)
+            node = sup
+        elif c == '{':
+            row = mrow()
+            node.append(row)
+            node = row
+        elif c == '}':
+            node = node.close()
+        elif c == '&':
+            entry = mtd()
+            node.close().append(entry)
+            node = entry
+        else:
+            raise SyntaxError(u'Illegal character: "%s"' % c)
+        string = string[skip:]
+    return tree
+
+
+def handle_keyword(name, node, string):
+    skip = 0
+    if len(string) > 0 and string[0] == ' ':
+        string = string[1:]
+        skip = 1
+    if name == 'begin':
+        if not string.startswith('{matrix}'):
+            raise SyntaxError(u'Environment not supported! '
+                              u'Supported environment: "matrix".')
+        skip += 8
+        entry = mtd()
+        table = mtable(mtr(entry))
+        node.append(table)
+        node = entry
+    elif name == 'end':
+        if not string.startswith('{matrix}'):
+            raise SyntaxError(u'Expected "\\end{matrix}"!')
+        skip += 8
+        node = node.close().close().close()
+    elif name in ('text', 'mathrm'):
+        if string[0] != '{':
+            raise SyntaxError(u'Expected "\\text{...}"!')
+        i = string.find('}')
+        if i == -1:
+            raise SyntaxError(u'Expected "\\text{...}"!')
+        node = node.append(mtext(string[1:i]))
+        skip += i + 1
+    elif name == 'sqrt':
+        sqrt = msqrt()
+        node.append(sqrt)
+        node = sqrt
+    elif name == 'frac':
+        frac = mfrac()
+        node.append(frac)
+        node = frac
+    elif name == 'left':
+        for par in ['(', '[', '|', '\\{', '\\langle', '.']:
+            if string.startswith(par):
+                break
+        else:
+            raise SyntaxError(u'Missing left-brace!')
+        fenced = mfenced(par)
+        node.append(fenced)
+        row = mrow()
+        fenced.append(row)
+        node = row
+        skip += len(par)
+    elif name == 'right':
+        for par in [')', ']', '|', '\\}', '\\rangle', '.']:
+            if string.startswith(par):
+                break
+        else:
+            raise SyntaxError(u'Missing right-brace!')
+        node = node.close()
+        node.closepar = par
+        node = node.close()
+        skip += len(par)
+    elif name == 'not':
+        for operator in negatables:
+            if string.startswith(operator):
+                break
+        else:
+            raise SyntaxError(u'Expected something to negate: "\\not ..."!')
+        node = node.append(mo(negatables[operator]))
+        skip += len(operator)
+    elif name == 'mathbf':
+        style = mstyle(nchildren=1, fontweight='bold')
+        node.append(style)
+        node = style
+    elif name == 'mathbb':
+        if string[0] != '{' or not string[1].isupper() or string[2] != '}':
+            raise SyntaxError(u'Expected something like "\\mathbb{A}"!')
+        node = node.append(mi(mathbb[string[1]]))
+        skip += 3
+    elif name in ('mathscr', 'mathcal'):
+        if string[0] != '{' or string[2] != '}':
+            raise SyntaxError(u'Expected something like "\\mathscr{A}"!')
+        node = node.append(mi(mathscr[string[1]]))
+        skip += 3
+    elif name == 'colon': # "normal" colon, not binary operator
+        node = node.append(mo(':')) # TODO: add ``lspace="0pt"``
+    elif name in Greek:   # Greek capitals (upright in "TeX style")
+        node = node.append(mo(Greek[name]))
+        # TODO: "ISO style" sets them italic. Could we use a class argument
+        # to enable styling via CSS?
+    elif name in letters:
+        node = node.append(mi(letters[name]))
+    elif name in special:
+        node = node.append(mo(special[name]))
+    elif name in functions:
+        node = node.append(mo(name))
+    elif name in over:
+        ovr = mover(mo(over[name]), reversed=True)
+        node.append(ovr)
+        node = ovr
+    else:
+        raise SyntaxError(u'Unknown LaTeX command: ' + name)
+
+    return node, skip
+
+def tex2mathml(tex_math, inline=True):
+    """Return string with MathML code corresponding to `tex_math`.
+
+    `inline`=True is for inline math and `inline`=False for displayed math.
+    """
+
+    mathml_tree = parse_latex_math(tex_math, inline=inline)
+    return ''.join(mathml_tree.xml())