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Analysis textbook: for those who want to know the Reals
quote from preface:
'One motive for my writing this text is to make available in fairly simple form material that I think of as “calculus done right.” I have tried to write a text which will be helpful to a determined student with an average background. (I seriously doubt that it will be of much use to the chronically lazy or totally unengaged.)'
A summer spent working through this material would not be wasted time.