def variable_closure(variables, casify):
 def render_variable(children):
  '\n        Replace greek letters, otherwise escape the variable names.\n        '
  varname = children[0].latex
  if (casify(varname) not in variables):
   pass
  (first, _, second) = varname.partition('_')
  if second:
   varname = u'{a}_{{{b}}}'.format(a=enrich_varname(first), b=enrich_varname(second))
  else:
   varname = enrich_varname(varname)
  return LatexRendered(varname)
 return render_variable

def variable_closure ( variables , casify ) : def render_variable ( children ) : varname = children [ 0 ] . latex if ( casify ( varname ) not in variables ) : pass ( first , _ , second ) = varname . partition ( '_' ) if second : varname = u'{a}_{{{b}}}' . format ( a = enrich_varname ( first ) , b = enrich_varname ( second ) ) else : varname = enrich_varname ( varname ) return LatexRendered ( varname ) return render_variable
wrap render_variable so it knows the variables allowed .