Moving forward, this repository will be the primary way of collaborating and contributing to the pi-base, and we'll be building and distributing tools to make that collaboration easier and richer.

The historical literature isn't always consistent on notation or terms. We adhere to the following conventions:

Where there is no contradiction, we use conventions established in the following texts:

• General Topology by Stephen Willard
• Topology by James Munkres

For the separation axioms, T_n ⇒ T_m whenever n ≥ m. For example regular is defined to assert that closed points and sets can be separated; T₃ is defined to be both regular and T₀. See e.g. wikipedia for more information.

If a property is named "locally P", then that means that every point in the space has a neighborhood base satisfying P for every member of the base. On the other hand, some authors define "locally P" to mean there is a single neighborhood satisfying P for each point. These definitions are equivalent for e.g. locally metrizabile, but are not equivalent in general (e.g. for locally compact). See this issue for discussion. We use the name "locally P by single neighborhoods" for the latter definition, where they differ.