Recursed is not recursive: A jarring result
Name
LIPIcs-ISAAC-2020-50.pdf
Description
Published version
Size
1.15 MB
Format
Adobe PDF
Checksum (MD5)
84b28c86c4e8a4d50e744f4eabf8d843
Author(s)
Demaine, ED
Kopinsky, J
Lynch, J
Date Issued
December 1, 2020
Journal
Leibniz International Proceedings in Informatics, LIPIcs
Citation
Demaine, ED, Kopinsky, J and Lynch, J. 2020. "Recursed is not recursive: A jarring result." Leibniz International Proceedings in Informatics, LIPIcs, 181.
Version
Final published version
Abstract
Recursed is a 2D puzzle platform video game featuring “treasure chests” that, when jumped into, instantiate a room that can later be exited (similar to function calls), optionally generating a “jar” that returns back to that room (similar to continuations). We prove that Recursed is RE-complete and thus undecidable (not recursive) by a reduction from the Post Correspondence Problem. Our reduction is “practical”: the reduction from PCP results in fully playable levels that abide by all constraints governing levels (including the 15 × 20 room size) designed for the main game. Our reduction is also “efficient”: a Turing machine can be simulated by a Recursed level whose size is linear in the encoding size of the Turing machine and whose solution length is polynomial in the running time of the Turing machine.
MIT Department
Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
Terms of Use
Creative Commons Attribution 3.0 unported license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.4230/LIPIcs.ISAAC.2020.50
