first set theory article
... that mathematicians disagree about whether a proof in Georg Cantor's first set theory article actually shows how to construct a transcendental number, or merely proves that such numbers exist?
... that mathematicians disagree about whether a proof in <a href="./Georg_Cantor" id="mwB_U" rel="mw:WikiLink" title="Georg Cantor">Georg Cantor</a>'s <b id="mwB_Y"><a class="mw-redirect" href="./Georg_Cantor's_first_set_theory_article" id="mwB_c" rel="mw:WikiLink" title="Georg Cantor's first set theory article">first set theory article</a></b> actually shows how to construct a <a href="./Transcendental_number" id="mwB_g" rel="mw:WikiLink" title="Transcendental number">transcendental number</a>, or merely proves that such numbers exist?