20.1 Universality of letter-bounded CFLs By Moses Ganardi July 1, 2020 Input: a context-free grammar for a language $L \subseteq a_1^* \dots a_n^*$ ($n$ is part of the input) Question: Is $L = a_1^* \dots a_n^*$? What is the complexity of the problem? Newer 20.2 Deterministic separability of nondeterministic timed languages Older 19.17 Existence of a universal amplifier of selection