My brother is a researcher of macroscopic things, like at the scale of universes. He infamously had a theory that mirrors are actually portals to another universe, but when you try to get in, your reflection also tries to get in to your world, thus blocking you. No one believed this (including me), but when he turned up missing, I started to speculate... The only clue he left was the note below.

The Note

There are two parts to the note. There are some clues at the top, and a series of symbols at the bottom.

The clues are:

  1. 1 + 1
  2. √16 + 10 - 2
  3. 12 / 2(3) + 1
  4. (navigator.oscpu.length % 2) + 7
  5. "1" + "0"
  6. 3(5)
  7. ℕ[0] + 20

And the symbols are:

nyaorohet heln:zptp)(

How to Answer

I need to know if my brother is actually in the mirror world! Please solve and explain each clue on the note, and draw a conclusion about where he is. Basically, the question is:

Is my brother in the mirror world?


Well, this is embarrassing. I left out ONE character that crucially changes the puzzle. I recently edited it back in. For those of you who have solved the individual clues, those answers should not change. However, transcribing those answers to the final answer has changed.

All I did was added the character t as the 9th character in the symbols list. If you have answered, please go back and change your final answer to use the new character set.



I wish I could accept more than one answer!


Ambiguity is the answer. (Don't take this literally; just needed the alliteration...)

3 (quite spoiling, use only if very stuck)

Find the answers to the questions, then note the corresponding symbol from the string. It may not make sense at first, even if you think you have found the answers... Make sure you find all of them.

4 (hint on clue 1)

This is a clue that many people not in the field wouldn't know. Go ask a logician... Even better yet, an electrical logician?!?

5 (Defeats a large part of the puzzle)

Each of the clues, except 5 and 6, have 2 answers, making two possible final answers (hence the parallel). You have to get all answers for all clues, then pick out which answer for each of the clues goes to which of the two final answers.

  • $\begingroup$ I think we need another hint $\endgroup$
    – nikki
    Aug 13, 2018 at 16:37

2 Answers 2


Starting with the numbers:

1. 1 or 2 (The OR gate, from @Nikki)
2. sqrt(16) + 10 - 2 = +- 4 + 10 - 2 = 12 or 4 (Unless I'm missing something, the positive root of 16 = 4, plus 10 is 14, less 2 is 12...)
3. 12/2 = 6*3 = 18 + 1 = 19; and 12/(2*3) = 12/6 = 2+1 = 3 (even though this second one isn't really correct BEDMAS)
4. 7 or 8 (any remainder with divisor 2 will be either 0 or 1....I'm not sure if there is a unique answer for all operating systems, but in Javascript navigator.oscpu returns a string which identifies the OS. "Windows NT 6.3" has an even number of characters -> would be 7.)
5. 10 (concatenation of "1" + "0" = "10")
6. 15
7. 21 and 20 (the 0th element of the natural numbers (if you wanted to index them that way) is either 1 or 0)

There seems to be

20 characters in the message, so taking the 21st character to be a space after the string, the sequence of characters 2-12-3-7-10-15-21 yields the string "ylahhz " which doesn't make sense.

With the additional letters, I'm getting (updated as per OP comments, thanks @yummypasta!)

"YEAH :(" and "NOPE :)", if you're glad to have your brother around; or "YEAH :)" and "NOPE :(" if you really wanted your brother to be trapped in the mirror world!

So I guess this means that

He is and he isn't! (Funny little mirror world duality!)

Final comment: this was done largely in collaboration with @nikki's answer below...which means if you like my answer, go and upvote @nikki's too!! :)

  • 1
    $\begingroup$ You are sooo close. Just read hint #5. Also, read my comments on @nikki's post for clue #7 (Actually, a quick Wikipedia search on Natural Numbers will suffice if you read just the intro!) $\endgroup$
    – yummypasta
    Aug 13, 2018 at 18:20
  • 1
    $\begingroup$ We have the same letters at least $\endgroup$
    – nikki
    Aug 13, 2018 at 18:38
  • 1
    $\begingroup$ Oh my, I just realized what I have done! I forgot ONE character in the string of characters. Please read my edit on the question. The answers to each of the clues should not change, but the final answer will. You should be able to solve it. (just mentioning @nikki here so they get the notification). So at this point, I guess, whoever edits their answer first and interprets the correct final answers will get the accepted checkmark? $\endgroup$
    – yummypasta
    Aug 13, 2018 at 19:15
  • 1
    $\begingroup$ You got it. I'm accepting your answer as opposed to @nikki 's answer, because you found most of the clues and were first to put together the final answer. At the end, there is supposed to be a smiley/frowny face emoticon, hence the : and parenthesis. Anyways, good job! $\endgroup$
    – yummypasta
    Aug 13, 2018 at 19:41
  • 1
    $\begingroup$ Aww! So close! :( $\endgroup$
    – nikki
    Aug 13, 2018 at 19:44

The answers from 1 to 7 are

1 or 2 (1+1=2 or, with new hint, + seems to be OR gate, so 1 + 1 is 1)
12 and 4
19 and 3
7 or 8
20 or 21

Using some answers given by El-Guest

I think

Each of 1 to 7 has 2 answers, and we should arrange the characters corresponding to the 2 numbers for each question and line them up one below the other (because the title says parallel)

I have



I can find NOPE in one word and YEAH in the other. I'm gonna go ahead and guess the brother is in the mirror world and not in the mirror world at the same time... (I think this goes well with the duality of answers for most questions)


Yeah : (open) meaning he's in the mirror world

  • $\begingroup$ I will update my answer soon after learning how to format text in markdown $\endgroup$
    – nikki
    Aug 9, 2018 at 4:59
  • $\begingroup$ Good job. Number 1 is incorrect, and you have yet to find 7. 7 is math related, look up the symbol. The reading in a mirror is incorrect, but once you find all the solutions, it will be more straightforward than you think. $\endgroup$
    – yummypasta
    Aug 9, 2018 at 6:12
  • $\begingroup$ number 1: 2 or 11? $\endgroup$
    – OfFPiR
    Aug 9, 2018 at 11:58
  • $\begingroup$ I think you got 1 right! For 7, that symbol represents the set of all natural numbers; I've also seen N[ ] used to represent a polynomial ring with natural number coefficients...but I'm not sure how that helps! $\endgroup$
    – El-Guest
    Aug 9, 2018 at 20:13
  • $\begingroup$ I don't know either! Still trying to think what can be done... $\endgroup$
    – nikki
    Aug 9, 2018 at 22:43

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