Problem 18
A useless state in a pushdown automaton is never entered on any input
string. Consider the problem of testing whether a pushdown automaton
has any useless states. Formulate this problem as a language and show
that it is decidable.
Computer Science Homework Solutions
#113155
Automata and Computability
A useless state in a pushdown automaton is never entered on any input string. Consider the problem of testing whether a pushdown automaton has any useless states. Formulate this problem as a language and show that it is decidable.
What is this?
By OTA - Overall OTA Rating
Mike Mikailov, PhD - 4.8/5
Purchase Cost Now
$2.19 CAD (was ~$11.97)
Included in Download
- Plain text response
- Attached file(s):
- Problem+A118[2]_Sol.doc
Why you can trust BrainMass.com
- Your Information is Secure
- Best Online Academic Help Service
- Students find real academic Success
- Automata and Computability - Let C be a language. Prove that C turing-recognizable if a decidable language D exists such that C = {x | y (x,y D)}.
- Automata and Computability (A125) - 1. Give an example in the spirit of the recursion theorem of a program in a real programming language (or a reasonable approximation thereof) that prints itself out.
- Automata and Computability - Show that, if P = NP then every language A P except A = 0 and A = * is NP-complete. See attached for full problem description.
- Automata and Computability - Let EQREX = {R,S | R and S are equivalent regular expressions}. Show that EQREX PSPACE. See attached file for full problem description.
- Automata and Computability - Let A = (attached) | R is a regular expression describing a language containing at least one string w that has 111 as a substring (i.e., w = x111y for some x and y)}. Show that A is decidable.
