You can find a PDF copy of An Introduction to General Topology by Paul E. Long (1971) at the Internet Archive. This site allows you to borrow the digital book or access restricted files with an account. The "Story" of the Book
The famous hierarchy: ( T_0, T_1, T_2 ) (Hausdorff), regular (( T_3 )), and normal (( T_4 )) spaces. Long explains why Hausdorff spaces are essential for uniqueness of limits and why normal spaces are required for Urysohn’s metrization theorem (introduced later in exercises).
An introduction to general topology by Paul E Long | Goodreads an introduction to general topology paul e long pdf link
Unlike some modern texts that can be "overly pedantic," Long’s approach is known for being accessible to students transitioning from advanced calculus to abstract mathematics.
Paul E. Long’s 1971 textbook, "An Introduction to General Topology," provides an accessible, classical approach to point-set topology suitable for undergraduates. The text covers essential topics including axiomatic foundations, topological spaces, and continuous functions, featuring ample exercises for skill development. A high-quality digital copy is available to borrow through the Internet Archive Internet Archive An introduction to general topology : Long, Paul E You can find a PDF copy of An
Exploring the Foundations: Paul E. Long 's " An Introduction to General Topology "
You can view or borrow a digital copy of the book through major online archives: Internet Archive : Offers the full 281-page text for digital borrowing. Open Library ISBN-10: 0134805762 ISBN-13: 978-0134805764
Course Notes: Introduction to Topology (UCR) offers a comprehensive "definition bank".