▁continuous ▁flow . ▁D ui ▁li an ▁were ▁not ▁only ▁s oph istic ated ▁and ▁effective ▁methods ▁of ▁passing ▁on ▁the ▁fighting ▁knowledge ▁of ▁the ▁older ▁generation , ▁but ▁they ▁were ▁also ▁essential ▁and ▁effective ▁training ▁methods . ▁The ▁relationship ▁between ▁single ▁sets ▁and ▁contact ▁sets ▁is ▁complicated , ▁in ▁that ▁some ▁skills ▁cannot ▁be ▁developed ▁with ▁solo ▁' sets ', ▁and , ▁convers ely , ▁with ▁du i ▁li an . ▁Unfortunately , ▁it ▁appears ▁that ▁most ▁traditional ▁combat ▁orient ed ▁du i ▁li an ▁and ▁their ▁training ▁method ology ▁have ▁disappeared , ▁especially ▁those ▁concerning ▁weapons . ▁There ▁are ▁several ▁reasons ▁for ▁this . ▁In ▁modern ▁Chinese ▁mart ial ▁arts , ▁most ▁of ▁the ▁du i ▁li an ▁are ▁recent ▁invent ions ▁designed ▁for ▁light ▁props ▁res emb ling ▁weapons , ▁with ▁safety ▁and ▁drama ▁in ▁mind . ▁The ▁role ▁of ▁this ▁kind ▁of ▁training ▁has ▁deg ener ated ▁to ▁the ▁point ▁of ▁being ▁useless ▁in ▁a ▁practical ▁sense , ▁and , ▁at ▁best , ▁is ▁just ▁performance . ▁ ▁By ▁the ▁early ▁Song ▁period , ▁sets ▁were ▁not ▁so ▁much ▁" ind ividual ▁isolated ▁technique ▁str ung ▁together " ▁but ▁rather ▁were ▁composed ▁of ▁techniques ▁and ▁counter ▁technique ▁group ings . ▁It ▁is ▁quite ▁clear ▁that ▁" sets " ▁and ▁" f ight ing ▁( two - person ) ▁sets " ▁have ▁been ▁instrument al ▁in ▁T CM ▁for ▁many ▁hundreds ▁of ▁years — even ▁before ▁the ▁Song ▁D ynast y . ▁There ▁are ▁images ▁of ▁two - person ▁weapon