Approximation schemes for P-complete problems? What work has been done on approximation schemes for $\mathsf{P}$-complete optimization problems? Would the desired approximation algorithms here be "fully log-space approximation schemes" or "fully $\mathsf{NC}$ approximation schemes", analogous to $\mathsf{FPTAS}$ for $\mathsf{NP}$ optimization problems?
This one seems related, although it focuses more on parallel time (NC) rather than the closely related space (L): http://www.springerlink.com/content/8hn2q8lvf3ukbbx0/