- Halting problem for one counter machines CM1_HALT
- Satisfiability of elementary, square, and uniform Diophantine constraints H10C_SAT, H10SQC_SAT, and H10UC_SAT
- Extensional Model of Z via Class Extensionality
- Halting problem for FRACTRAN programs FRACTRAN_HALTING
- Halting problem for the call-by-value lambda-calculus HaltL
- Halting problem for Minsky machines
- Halting problem for two counter Minsky machines MM2_HALTING
- Halting problem for Minsky machines
- Halting problem for Minsky machines MM_HALTING
- Post Correspondence problem PCP
- Solvability of finite multiset constraints FMsetC_SAT
- Halting problem for binary stack machines BSM_HALTING
- Halting problem for binary stack machines BSM_HALTING
- Halting problem for simple binary single-tape Turing machines HaltSBTM
- Halting problem for multi-tape and single-tape Turing machines HaltMTM and HaltTM 1