- Preliminaries
- Definitions
- Reducing MPCP to PCP
- Reducing String Rewriting to MPCP
- Reducing the Reachability of Turing Configurations to String Rewriting
- Reducing the Halting Problem to String Rewriting
- Reducing the Halting Problem to MPCP
- Reducing String Rewriting to Restricted String Rewriting
- Reducing Restricted String Rewriting to PCP
- Undecidability of PCP