Pre-Frege may not have both maps (but it has at most one).
Pre-Frege may not have both maps (but it has at most one).

pleroy/Principia,mockingbirdnest/Principia,mockingbirdnest/Principia,mockingbirdnest/Principia,pleroy/Principia,pleroy/Principia,pleroy/Principia,mockingbirdnest/Principia