Abstract:We characterize spaces with $\sigma $-$n$-linked bases as specially embedded subspaces of separable spaces, and derive some corollaries, such as the $\bold c$-productivity of the property of having a $\sigma $-linked base.
Keywords: separable, c.c.c., $\sigma $-centered base, $\sigma $-$n$-linked base, $I_n$-embedding, $I_{<\omega }$-embedding, product, Martin's Axiom, $C_p$-spaces
AMS Subject Classification: Primary 54D65, 54D70; Secondary 54B10, 54C25