31 Is a push-down automaton with two stacks equivalent to a turing machine? 2012-07-19T10:50:44.883

30 Are there inherently ambiguous and deterministic context-free languages? 2012-03-07T20:56:08.960

22 Is this strange language context free? 2013-04-26T17:56:00.657

20 Decide whether a context-free languages can be accepted by a deterministic pushdown automaton 2012-05-21T09:30:46.410

15 Construct a PDA for the complement of $a^nb^nc^n$ 2012-12-05T18:20:04.433

15 Is it decidable whether a pushdown automata recognizes a given regular language? 2015-04-25T10:01:08.667

14 Push Down Automatons "guess" - what does that mean? 2013-07-23T17:57:55.890

12 Computing the intersection of two NPDA where it is possible 2014-03-27T01:19:07.693

11 Does the language of Regular Expressions need a push down automata to parse it? 2012-05-20T03:26:18.503

10 How to prove that ε-loops are not necessary in PDAs? 2012-06-12T13:47:52.250

9 Is non-determinism in a non-deterministic turing machine different from that of finite automata and push down automata? 2015-10-13T15:14:34.813

8 How do I show that whether a PDA accepts some string $\{ w!w \mid w \in \{ 0, 1 \}^*\}$ is undecidable? 2012-11-12T05:00:51.627

8 Is there a strictly non-deterministic one-counter language whose complement is one-counter? 2013-03-19T15:44:35.443

8 Is the language $\{0^n 1^m \mid n \text{ and } m \text{ are co-prime}\}$ context-free? 2013-04-11T18:04:33.373

8 Paper with proof that $L=\{ a^n b^n \mid n \geq 0 \} \cup \{ a^n b^{2n} \mid n \geq 0 \}$ is not Deterministic Context Free? 2013-05-29T23:32:51.367

8 Demonstrate that DPDA is closed under complement by construction 2013-12-10T00:34:01.010

7 Are DCFLs closed under reversal? 2014-10-07T13:05:04.923

7 Why does Non Determinism not enhance FA like it does for PDA 2017-03-07T23:50:38.097

6 If $L$ is context-free and $R$ is regular, then $L / R$ is context-free? 2012-05-17T16:19:42.050

6 Converting a context free grammar to a PDA -- is my solution correct? 2011-11-05T19:34:40.697

6 prove no DPDA accepts language of even-lengthed palindromes 2013-04-27T06:52:11.577

6 Myhill-Nerode style characterization of CFL? 2013-06-12T21:49:16.247

6 is it possible to minimize pushdown automata? 2015-01-21T19:07:09.293

6 Decidability of halting problem for DPDAs with $\epsilon$-transitions? 2016-06-27T13:09:28.767

5 Deterministic context-free languages are closed under regular right-product 2012-11-30T10:53:41.263

5 why are deterministic PDAs not closed under concatenation? 2012-12-11T12:49:25.547

5 Reference request: proof that if $L \in DCFL$, then $L \Sigma^* \in DCFL$ 2013-07-09T17:23:08.623

5 How to get 2-state PDA for CFG? 2014-01-24T18:53:40.317

5 How to find a Deterministic PDA for an intersection of languages 2014-02-05T04:09:47.847

5 Intersection of two NPDAs 2014-03-26T02:34:19.813

5 Which class of languages is accepted by PDA when we restrict the stack to logarithmic size? 2015-01-25T12:48:56.483

5 Can we build a nondeterministic decider PDA using two PDAs accepting a language and its complement? 2015-01-27T01:11:01.010

5 Why is $\{a^n b^m c^p: n\neq m\} \cup \{a^n b^m c^p: m\neq p\}$ an inherently ambiguous language? 2015-03-22T08:56:39.737

5 Why can PDAs only write one symbol to the stack according to this definition? 2016-08-08T14:07:47.593

5 Do NPDA work in parallel? 2017-08-02T16:40:50.093

4 How does a two-way pushdown automaton work? 2012-03-23T15:39:20.283

4 Convert CFG to PDA 2013-04-10T03:00:30.087

4 Designing a PDA w/o $\epsilon$-moves and $\leq 2$ states to accept an $\epsilon$-free CFL by final state 2013-04-15T01:15:08.810

4 Constructing a PDA for the language $\{a^m b^n : m < 2n < 3m \}$ 2013-10-09T00:28:08.143

4 Incorporating newline-as-statement-terminator heuristics into context-free languages 2014-07-24T11:27:55.987

4 Simulate NPDAs with DTMs using only polynomial overhead 2014-11-13T10:52:50.290

4 Proof that CFL aren't closed under intersection using synchronous parallel (N)PDA composition 2015-06-17T20:26:24.703

4 pda: transformation between acceptance by empty stack and final states 2015-07-06T22:13:08.040

4 How powerful is a k-stack pushdown automaton with a unary stack alphabet? 2015-10-05T17:29:30.423

4 Parsing CFLs (simulating PDA vs CYK algorithm) 2016-10-13T03:06:46.460

4 Equivalence of PDA and a counting PDA 2016-12-25T14:39:08.717

4 Is $L=\{a^ib^jc^k : i\leq j\leq k\}$ context-free? 2017-01-01T13:11:14.423

3 Are Turing machines more powerful than pushdown automata? 2012-03-22T20:00:29.897

3 Push down automata for $\{a^n b^n c^n | n \ge 0\}$ 2013-01-17T13:57:17.883

3 Proving that a specific language is a CFL, and that another language is not a CFL 2013-03-10T21:21:27.903

3 Give CFG and PDA for the words that start and end with the same symbol 2013-04-04T01:15:46.140

3 Is the language $L = \{ a^ib^j \mid i\ \nmid\ j \ \} $ context free? 2013-04-19T10:08:37.820

3 Pushdown automation where number of letter `a` is at least as twice as letter `b` in the word 2013-05-14T08:51:09.267

3 Definition of deterministic pushdown automaton 2013-08-16T22:04:47.060

3 Creating a Deterministic Push Down Automata 2014-02-11T04:35:31.363

3 Is "duplicate" in RPN enough for replacing variable binding in term expressions? 2014-10-21T09:02:20.533

3 What additional expressivity does polyvariance give in pushdown CFA? 2015-04-27T00:37:02.120

3 When does a PDA split? 2015-10-08T03:43:52.533

3 What are some applications of 2 stack pushdown automata? 2015-12-02T15:44:52.583

3 How to understand pushdown automata intuitively? 2016-04-25T02:52:53.507

3 Is a PDA's stack size linear bounded in input size? 2016-05-26T20:00:25.317

3 Union of a Deterministic Context-free language and a Regular Language is a Deterministic Context-free Language 2016-05-29T13:44:00.077

3 Why DCFL is not closed under kleene star? 2016-06-04T15:46:22.550

3 Proof that PDA's with different definitions have same expressive power 2016-10-17T09:18:29.887

3 PDA with an unusual double inequality 2016-10-29T01:53:14.477

3 Is $L / R$ context free? 2016-11-02T14:25:26.303

3 PDA for { xy : |x| = |y|, x ≠ y} from its grammar, and intuition behind it 2016-12-02T14:43:05.967

3 Algorithm to detect if word belongs to pushdown automaton 2016-12-16T13:41:32.047

3 Equivalent DPDA that always halts for every DPDA with empty stack language 2016-12-19T12:54:45.117

3 When does a PDA halt? 2016-12-20T20:52:58.797

3 CFL and inverse homomorphism 2017-03-06T10:26:55.073

3 Understanding context free grammars in conjunction with PDA 2017-03-22T11:54:12.870

3 Which of the following languages is accepted by this Pushdown Automaton? 2017-04-18T14:23:56.950

3 Do deterministic context free grammars always have corresponding deterministic push down automata? 2017-05-08T01:20:24.153

3 simulation of PDA with 2-tape Turing machine 2017-06-24T13:45:12.743

3 Working of NPDA 2017-10-08T18:34:32.320

3 Systematic approach or algorithm for designing a pushdown automata that accepts a langauge 2017-12-24T11:23:11.060

3 Basic doubt in converting PDA to DPDA 2018-01-30T04:54:30.480

3 Can every DFA be simulated by a PDA? 2018-01-30T21:04:27.147

2 Eliminating useless productions resulting from PDA to CFG converison 2012-06-26T20:28:39.280

2 Context-free grammar to a pushdown automaton 2012-07-13T18:08:44.950

2 Constructing deterministic PDA for not regular language 2012-10-22T19:53:24.143

2 CFG and PDA for the grammar that has perfectly nested parentheses and brackets 2012-11-17T18:39:11.147

2 How can one simulate a PDA with a FIFO queue PDA? 2012-11-29T00:21:40.543

2 Constructing PDA to accept language { $a^i b^j c^k \mid i,j,k \geq0, i+2k = j$ } 2013-03-06T14:58:56.853

2 Constructing PDA for $a^{2n} b^{3n}$ 2013-03-10T14:50:24.700

2 Syntax of a Pushdown Automata transition function 2013-04-09T21:30:06.050

2 Cartesian construction of PDA and DFA 2013-04-10T18:43:39.247

2 PDA for this context-free grammar 2013-05-07T19:32:21.060

2 If a parser can parse a non-deterministic grammar, is the parser non-deterministic? 2013-07-22T17:38:48.407

2 Constructing a Context Free Grammar for checking non-equality of strings 2013-08-22T12:20:47.063

2 Can we push and pop both at a single transition in a PDA? 2013-11-06T16:39:50.133

2 Is $\{w:w\in(a+b+c)^*, n_a(w) > n_b(w)>n_c(w)\}$ context-free? 2013-11-29T17:48:42.330

2 Relaxing the stack in a push down automata 2013-12-13T16:15:38.797

2 Why Deterministic PDA accepts $\epsilon$ input but DFA not 2014-03-10T02:06:20.490

2 Good introductions to Formal Language Theory and Formal Grammars 2014-04-08T18:09:27.717

2 Language of binary strings divisible by 7 2014-12-15T09:49:28.887

2 Is a k counter automata a special kind of PDA? 2015-02-16T00:29:49.393

2 When do we need to change the state of a push down automata? 2015-04-11T14:22:05.227