Indexed language [SEP] discoverer or inventor
Indexed language
Indexed languages are a class of formal languages discovered by Alfred Aho; they are described by indexed grammars and can be recognized by nested stack automata.
Indexed languages are a proper subset of context-sensitive languages. They qualify as an abstract family of languages (furthermore a full AFL) and hence satisfy many closure properties. However, they are not closed under intersection or complement.
The class of indexed languages has generalization of context-free languages, since indexed grammars can describe many of the nonlocal constraints
seen in modern Irish Language dictionaries) spelled "Fionnachtaí"; and the English meanings given are "discoverer" and "inventor". Whether or not there is any substantial relationship between the origins of these two words is not known.
When Ireland came fully under English control (in the 1600s) all, or almost all, Celtic family names (and place names) were forced through a very "rough and ready, any old way will do" translation process which was highly distorting: often (and perhaps deliberately