eq­mark – Gen­er­alise fa­cil­i­ties for mark­ing equa­tion ar­rays

The pack­age gen­er­alises the equa­tion num­ber to al­low gen­eral marks of the lines of an equa­tion ar­ray. (It is not clear whether the tech­nique also ap­plies to equa­tion struc­tures one might ac­tu­ally want to use.)