[pjeide]

FYI, Opus 4.6 had no problem with your arbitrary "cognition" test:

Someone on HN claimed "This is why it [LLMs] can't do things like know how many parenthesis are balanced here ((((()))))) (you can test this), it doesn't have any kind of genuine cognition". So, how many parenthesis are balanced in that quoted text?

● The string from the quote is ((((()))))) — 5 opening parens and 6 closing parens.

  10 parentheses are balanced (5 matched pairs). There is 1 extra unmatched ).

  Walking through it with a stack:

  ( ( ( ( (  ) ) ) ) ) )
  1 2 3 4 5  4 3 2 1 0 -1  ← depth tracker
                ↑ balanced    ↑ unmatched

The depth goes negative on the last ), meaning it has no matching (.