Coaction (source code)

= Coaction
{title2=$\rho:M\to M\otimes C$}

The structure map of a <comodule>; a right coaction satisfies $(\rho\otimes1)\rho=(1\otimes\Delta)\rho$ with coherent parentheses, and $(1\otimes\varepsilon)\rho$ is the inverse right <unitor>.