message: Rename x to output_row
diff: @@ -155,11 +155,11 @@ setting `t[id][row][col] = 0` for all `w < col <= W`.
  Form the combined table by concatenating all of these tables
  `FixedTable = t[0] || t[1] || t[2] || ...`
  and store in `TableID` the table ID that the corresponding row came from.
  -Then, for every `x` and `y`, we have
  +Then, for every `output_row`, we have
  ```
  -FixedTable[x][col] = t[id][row][col]`
  -TableID[x] = id
  -where x = len(t[0]) + len(t[1]) + ... + len(t[id-1]) + row
  +FixedTable[output_row][col] = t[id][row][col]`
  +TableID[output_row] = id
  +where output_row = len(t[0]) + len(t[1]) + ... + len(t[id-1]) + row
  ```
  This can be encoded as `W+1` polynomials in the constraint system, which we
  