If you find the PDF, print out Chapter 10 (Homotopy). Read it in a coffee shop. Watch people stare as you mutter "Simply connected" under your breath. That is the Dugundji experience. Have you wrestled with the Dugundji dragon? Let me know in the comments how far you got before you had to look up a solution.
Is it outdated? In typesetting, yes. In mathematical rigor, no. Dugundji’s topological foundation is still the bedrock for many working topologists. Topology -Dugundji-.pdf
If you have spent any time in graduate-level mathematics forums or asked a topologist for a "tough but rewarding" text, you have inevitably heard the whisper: Dugundji . If you find the PDF, print out Chapter 10 (Homotopy)
His section on contains the famous exercise: "A topological space is T1 iff every singleton is closed." That is the warm-up . The final exercise in that section usually takes an hour. Verdict: Keep it on your hard drive The Dugundji PDF is not a beach read. It is a reference weapon. I keep it open on my second monitor whenever I encounter a weird statement about "perfectly normal spaces" or "fiber bundles." That is the Dugundji experience