A continuous map 𝑓:𝑋→𝑌 between topological spaces is locally injective at a point𝑥∈𝑋 if 𝑥 has an (open) neighbourhood 𝑈 such that 𝑓↾𝑈 is an injection.
It is locally injective if it is locally injective at every point. #m/def/topology
Properties
Every injection between topological spaces is a local injection