The Missing Step

Student A was delighted when, in his final year in grad school, a joint paper with his faculty thesis supervisor, Professor B, was accepted at a competitive symposium in Theoretical Computer Science. The paper sketched the proof of a conjecture in complexity theory which had been the subject of a half-dozen prior papers. Student A's presentation was heard favorably by experts at the symposium, and afterward Student A began the detailed write-up of the proof for inclusion in his thesis.

But now, midway through the write-up, he realizes he cannot prove an essential lemma which had earlier seemed routine to both him and Professor B. He tells Professor B, and after a couple of days' work they realize that they had overlooked a serious lacuna in the proof when they published their symposium paper.

Professor B says they are obligated to publish an erratum in the following year's symposium volume. The deadline for submissions to next year's volume has formally just passed, but Professor B thinks they can still squeeze the erratum in if they mail it promptly. Student A thinks that with a few more weeks to think about it, he might be able to fill the lacuna.

• What are Professor B and Student A's responsibilities to report the gap in their proof?
• If Professor B and Student A disagree about responding, how might they resolve this disagreement?