Thank you for your comment on my article. I think I've managed to fix the proof by implementing a tag system. Would you (anyone) mind reviewing my code [1][2]? The key point is using back references, which I think gave us capabilities beyond regular expressions to achieve Turing completeness. However, I'm not very familiar with tag systems, and I'm worried I might have missed something.

[1] https://onecompiler.com/bash/42mux2442 [2] https://onecompiler.com/bash/42mux3nf8