On pp 46 of his Eisenstein Ideal paper, Mazur states Theorem I.4 and in the discussion that follows, he mentions 'a standard patching argument' that completes the proof. I was wondering whether this is the same as the gluing lemma that's described in Hartshorne, or is Mazur referring to something else? I'd appreciate if someone can fill me in on the details or perhaps direct me to some reference.
