Convince the Dean to grant tenure on the basis of excellent teaching. Use free beer to bribe your class into providing outstanding teaching evaluations. Observe that at least one tenured professor was denied tenure at another oranization. Thus, the set of all tenured professors contains a member who was not tenured. Argue that obtaining membership in such a set is equivalent to solving the halting problem.
Programming languages approach.
Argue that the ambiguity invalidates the requirements. Then devise an obscure, but unambiguous grammar that generates tenure requirements. Point out that you have fulfilled the only set of unambiguous requirements available.