Undecidable Problems
Some questions that are undecidable for wider classes of grammars become decidable for context-free grammars; e.g. the emptiness problem (whether the grammar generates any terminal strings at all), is undecidable for context-sensitive grammars, but decidable for context-free grammars.
Still, many problems remain undecidable. Examples:
Read more about this topic: Context-free Grammar
Famous quotes containing the word problems:
“As our disorderly, competitive technological society is piling up its victims and constantly developing new problems of maladjustment, we must use our scientific knowledge to determine the cause and prevention of suffering rather than putting all our emphasis on its alleviation ...”
—Agnes E. Meyer (1887–1970)