Left-separated topological spaces under Fodor-type Reflection Principle (Combinatorial and Descriptive Set Theory)
Sakaé Fuchino · Institutional Repositories DataBase (IRDB) · 2008
Assuming Fodor-type Reflection Principle, we prove that every $T_{1}$ -space with a point countable base is left-separated if all of its subspaces of cardi- nality $\leq\aleph_{1}$ are left-separated.This result improves a theorem bv Fleissner [4] who proved the same assertion under Axioin R. 2000 Mathern