Gruppenoperation/Assoziativität/Diagramm

${\begin{matrix}G\times G\times X&{\stackrel {\mu \times \operatorname {Id} _{X}}{\longrightarrow }}&G\times X&\\\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\!\operatorname {Id} _{G}\times \nu \downarrow &&\downarrow \nu \!\!\!\!\!&\\G\times X&{\stackrel {\nu }{\longrightarrow }}&X&\!\!\!\!\!\\\end{matrix}}$