Let $M$ be a smooth manifold. If $X$ and $Y$ are two Whitney objects, i.e. subsets with a given Whitney stratification, then $X$ and $Y$ are transverse if each stratum of $X$ is transverse to each stratum of $Y$. This definition confuses me: if $S\subset X$ is a stratum and $R\subset Y$ is another stratum, and $$\dim S+\dim R < \dim M$$ then how to define the transversal intersection of $S$ and $R$ in $M$?
