A
Alex
I have to write a java program to test if a word w ¤ L(G) for a context
sensitive grammar G.
Can anybody help me?
Thx in advance!
sensitive grammar G.
Can anybody help me?
Thx in advance!
Alex said:I have to write a java program to test if a word w ¤ L(G) for a context
sensitive grammar G.
Can anybody help me?
Oliver said:Alex said:I have to write a java program to test if a word w ¤ L(G) for a
context sensitive grammar G.
Can anybody help me?
http://en.wikipedia.org/wiki/Context-sensitive_grammar
<quote>
The decision problem that asks whether a certain string s belongs to the
language of a certain context-sensitive grammar G, is PSPACE-complete.
Indeed, there are even some context-sensitive grammars whose fixed
grammar recognition problem is PSPACE-complete.
[...]
That makes them totally unworkable for practical use, as the general
algorithm would take exponential time. Ongoing research on computational
linguistics has focused on formulating other classes of languages that
are "mildly context-sensitive" whose decision problems are feasible,
such as tree-adjoining grammars, coupled context-free languages, and
linear context-free rewriting systems. The languages generated by these
formalisms properly lie between the context-free and context-sensitive
languages.
</quote>
Alex said:I knew that this was a great decidability problem....but isn't there any
algorithm to do it ?
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