Talk:2DChanger

TC proof sketch

This construction searches a zero cell while moving right, which can probably help prove it TC:

      + +
      < } 
      } <  
 +a}<}+ + 
 +    +  

Assumes IP is at a and direction is right --ChuckEsoteric08 (talk) 11:55, 28 June 2026 (UTC) Only difficulty is to make IP be inside that loop to get to a --ChuckEsoteric08 (talk) 12:19, 28 June 2026 (UTC) Okay I improved it and it looks like this:

a}<+   ++
   }   <}
   <   }<
   +}<}++b
   +   + 

Assumes that current cell is 0, end point is at b with instruction pointer moving right. If }<} is replaced by }<}}< it would be an infinite loop --ChuckEsoteric08 (talk) 12:31, 29 June 2026 (UTC)

Reversible Brainfuck translation

Turns out Reversible Brainfuck style loop is possible:

[abc]def

Becomes:

++   ++   
<}   <}   
}<   }<   
++abc++def
}     <   
<     }   
+     +   
 +   +    

So it proves that it is Turing-complete. Nested loops would then be:

[abc[def]ghi]

   ++   ++   
   <}   <}   
   }<   }<   
             
             
             
abc++def++ghi
             
             
             
             
   }     <   
   <     }   
   +     +   
    +   +    

Which would be wrapped up in previously mentioned loop --ChuckEsoteric08 (talk) 18:28, 26 August 2026 (UTC)