if not modules then modules = { } end modules ['math-ext'] = {
    version   = 1.001,
    comment   = "companion to math-ini.mkiv",
    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
    copyright = "PRAGMA ADE / ConTeXt Development Team",
    license   = "see context related readme files"
}

-- local basename = file.basename
-- local sortedhash  = table.sortedhash
--
-- local mathematics     = mathematics
-- local extras          = mathematics.extras or { }
-- mathematics.extras    = extras
--
-- local characters      = characters
-- local chardata        = characters.data
-- local mathpairs       = characters.mathpairs
--
-- local trace_virtual   = false
-- local report_math     = logs.reporter("mathematics")
--
-- trackers.register("math.virtual", function(v) trace_virtual = v end)
--
-- local mathplus        = { }
--
-- function extras.add(unicode)
--     local min = mathematics.extrabase
--     local max = min + 0xFFF
--     if unicode >= min and unicode <= max then
--         if chardata[unicode] then
--             mathplus[unicode] = true
--         else
--             report_math("extra %U is not a registered code point",unicode)
--         end
--     else
--         report_math("extra %U should be in range %U - %U",unicode,min,max)
--     end
-- end
--
-- function extras.copy(target,original)
--     local characters = target.characters
--     local properties = target.properties
--     local parameters = target.parameters
--     for unicode in sortedhash(mathplus) do
--         local extradesc  = chardata[unicode]
--         local nextinsize = extradesc.nextinsize
--         if nextinsize then
--             local extrachar = characters[unicode]
--             local first     = 1
--             local charused  = unicode
--             if not extrachar then
--                 for i=1,#nextinsize do
--                     local slot = nextinsize[i]
--                     extrachar = characters[slot]
--                     if extrachar then
--                         characters[unicode] = extrachar
--                         first = i + 1
--                         charused = slot
--                         break
--                     end
--                 end
--             end
--             if not extrachar then
--                 if trace_virtual then
--                     report_math("extra %U in %a at %p with class %a and name %a is not mapped",
--                         unicode,basename(properties.fullname),parameters.size,
--                         extradesc.mathclass,extradesc.mathname)
--                 end
--             elseif not extrachar.next then
--                 local nextused = false
--                 for i=first,#nextinsize do
--                     local nextslot = nextinsize[i]
--                     local nextbase = characters[nextslot]
--                     if nextbase then
--                         local nextnext = nextbase and nextbase.next
--                         if nextnext then
--                             local nextchar = characters[nextnext]
--                             if nextchar then
--                                 extrachar.next = nextchar
--                                 nextused = nextslot
--                                 break
--                             end
--                         end
--                     end
--                 end
--                 if trace_virtual then
--                     if nextused then
--                         report_math("extra %U in %a at %p with class %a and name %a maps onto %U with next %U",
--                             unicode,basename(properties.fullname),parameters.size,charused,
--                             extradesc.mathclass,extradesc.mathname,nextused)
--                     else
--                         report_math("extra %U in %a at %p with class %a and name %a maps onto %U with no next",
--                             unicode,basename(properties.fullname),parameters.size,charused,
--                             extradesc.mathclass,extradesc.mathname)
--                     end
--                 end
--             else
--                 if trace_virtual then
--                     report_math("extra %U in %a at %p with class %a and name %a maps onto %U with no next", -- own next
--                         unicode,basename(properties.fullname),parameters.size,charused,
--                         extradesc.mathclass,extradesc.mathname)
--                 end
--             end
--         end
--     end
-- end
--
-- utilities.sequencers.appendaction(mathactions,"system","mathematics.extras.copy")