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qid 10589 · computer science

Question: The language {ww | w in (0 + 1)*} is

  1. accepted by some Turing machine, but by no pushdown automaton
  2. context-free, but not regular
  3. accepted by some finite automaton, but not pushdown automaton
  4. accepted by some Turing machine and some pushdown automaton
  5. accepted by any context-free grammar, but not regular
  6. accepted by some context-free grammar, but not Turing machine
  7. regular, but not context-free
  8. accepted by some pushdown automaton, but not context-free
  9. not accepted by any Turing machine

Our answer: A. accepted by some Turing machine, but by no pushdown automaton Source quote machine-checked (exact quote)

A machine check confirms the quoted words appear at the source. A person has not yet reviewed these. EARN MARKS as a Human Reviewer

How it was answered

Multi-step solver (maze), replayed by code

card: maze · card sha256 69e524cace9fc342…

Current source

Wikipedia, "Context-free language"

https://en.wikipedia.org/wiki/Context-free_language

“The context-free nature of the language makes it simple to parse with a pushdown automaton.”

Source quote machine-checked (exact quote)

retrieved 2026-09-18T01:18:05.512Z

page text sha256 3dfd3e8d3231922d… · content sha256 069fcca5f3bab189…

addendum maze_qid10589_b4_maze_input_ADDENDUM_source_rs20260918T011805Z · sha256 20b29049593fa949… · replaces the version below, addendum sha256 63b7a50098c7f3ee…

Earlier version (superseded)

No public source has been found for this card yet (3 places checked internally).

addendum maze_qid10589_b4_maze_input_ADDENDUM_source · sha256 63b7a50098c7f3ee…

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