deterministic context-free language

In formal language theory, deterministic context-free languages (DCFL) are a proper subset of  context-free languages. They are the context-free languages that can be accepted by a deterministic pushdown automaton. DCFLs are always unambiguous, meaning that they admit an unambiguous grammar, but any (non-empty) DCFLs also admit ambiguous grammars. There are non-deterministic unambiguous CFLs, so DCFLs form a proper subset of unambiguous CFLs.