Referenced by:

• idempotent
• idempotents-and-projections
• linear-subspace
• topology-2nd-countability-preserved-by-subspaces
• topology-closed-subspace-of-paracompact-is-paracompact
• topology-closures-in-subspace-topologies
• topology-connected-sandwich
• topology-continuity
• topology-locally-compact-hausdorff-iff-homeomorphic-with-open-subspace-of-compact-hausdorff