Source: /cirosantilli/covering-space

= Covering space
{wiki}

Basically it is a larger space such that there exists a <surjection> from the large space onto the smaller space, while still being compatible with the <topology> of the small space.

We can characterize the cover by how injective the function is. E.g. if two elements of the large space map to each element of the small space, then we have a <double cover> and so on.