▁taught ▁by ▁Yang ▁Sh ao - hou , ▁who ▁was ▁techn ically ▁a ▁generation ▁senior ▁to ▁their ▁father . ▁Both ▁Yang ▁Sh ao - hou ▁and ▁Wu ▁Ch ien - ch ' ü an ▁were ▁famous ▁for ▁their ▁" small ▁circle " ▁mart ial ▁expert ise . ▁The ▁mot ions ▁of ▁t ' ai ▁chi ▁ch ' uan ▁forms ▁and ▁pushing ▁hands ▁are ▁all ▁based ▁on ▁different ▁s ized ▁circles , ▁small ▁circle ▁movements ▁in ▁the ▁forms ▁and ▁applications ▁follow ▁a ▁more ▁compact ▁path way ▁for ▁different ▁le verage ▁applications ▁than ▁larger ▁circles . ▁ ▁In ▁the ▁ 1 9 2 0 s ▁Wu ▁K ung - ts ao ▁served ▁first ▁as ▁an ▁inf antry ▁officer ▁in ▁the ▁Th ir teenth ▁Brigade ▁of ▁the ▁National ist ▁army ▁until ▁ 1 9 2 9 , ▁then ▁later ▁as ▁a ▁mart ial ▁art ▁instruct or ▁for ▁the ▁Hun an ▁Mart ial ▁Arts ▁Training ▁Centre ▁as ▁well ▁as ▁an ▁instruct or ▁for ▁the ▁famous ▁Ch ing ▁Wu ▁mart ial ▁art ▁school . ▁During ▁the ▁ 1 9 3 0 s , ▁he ▁wrote ▁a ▁well - known ▁comment ary ▁on ▁the ▁classic ▁writ ings ▁in ▁ 4 0 ▁chap ters ▁on ▁t ' ai ▁chi ▁ch ' uan ▁that ▁his ▁grand father ▁had ▁inherited ▁from ▁Yang ▁Pan - hou . ▁His ▁comment ary ▁( including ▁the ▁original ▁ 4 0 ▁chap ters ) ▁was ▁published ▁as ▁Wu ▁Ch ia ▁T ' ai ▁Chi ▁Ch ' uan ▁( <0xE5> <0x90> <0xB3> 家 太 <0xE6> <0xA5> <0xB5> 拳