Decided to (re)watch the english dub of Death Note after 1) Watching Just Write’s analysis of the show’s pacing; 2) Considering the fact that the US live action airs in just four days; 3) Deciding to say fuck it and not study for my IB prelim papers. Came to realise exactly how broken the death note is. It’s so fucking obvious that I can’t believe I didn’t see it the first time I watched the show.

Abstract: A partial solution to Light’s dilemma in Encounter (the ninth episode) upon L’s reveal is demonstrated; it involves the use of conditional statements and deaths from the death note as a determiner of the truth value of said statements. A cursory discussion of the consequences is held.

Regarding the possible killing of Hideki Ryuga (the actor) rather than Hideki Ryuga (the detective) on the assumption that both have the same name, and the condition that a name and a face is required to kill, which may lead to the death of the wrong target and a further loss of anonymity— Light need not have been particularly concerned, since logical operators may have been usable:

Hideki Ryuga dies due to a car accident on the way to To-Oh university on one of the days he chooses to do so iif he is the mastermind behind the televised announcement that was broadcasted in the Kanto region wherein an individual named L. Lind Tailor was killed using this notebook while he was on-air.

Additionally, if the death note would accept such commands (on the premise that it is an omniscient black box–which is plausible since it 1) Must know every name and face in the world [HTU I rule 1&2]; 2) Have the ability to read mental content [HTU I rule 2]; 3) Comprehend possible states of reality [HTU VI rule 1] as well as intentionality behind language by virtue)–then it could be used to solve for other interesting things with interesting if not life-changing consequences:

Determining whether or not Elon Musk is correct

Iff alien lifeforms with human-level intelligence exists, then [insert name here] dies of a heart attack. Determining whether or not I should bother with university

Iff the value of one bitcoin exceeds and does not drop below USD$5,000 by the end of 31 August 2017, then [insert name here] dies of a heart attack. Determining whether or not I should seriously start studying Math

Iff goldbach’s conjecture can be proven by mathematical techniques within the corpus of currently published academic literature, then [insert name here] dies of a heart attack.

(The examples above may need rephasing due to HTU VIII rule 1, which seems to imply that a name must be written in front of any other information, but this may be a false inference.)

(Edit: It appears that I have misinterpreted the nature of HTU I rule 1. The term ‘shall’ is equivalent to ‘will’, therefore a valid person whose name is written in the death note with the proper procedure has to die no matter what. As such, the only way to determine the truth value would be to tie the antecedent and its inverse to distinct causes of death, i.e. A dies of respiratory failure iff x is true; and A dies by committing suicide iff x is false. Also note that this phraseology also covers the special case wherein x is neither true nor false, in which event A simply dies of a heart attack.)

If these are valid inputs that yield valid (if deadly) outputs, then the value of the death note is infinite, with it being able to exchange one human life for one bit of information binary division within the domain of discourse.* By these means, the user of a death note is practically omniscient on top of being a de facto master of death. This, of course, is contingent on the fact that the user is willing and able to take the time to adjust the granularity of the input statements, and that there is a constant supply of humans over 780 days old [HTU IX rule 1] whom which the user can reliably enquire of or be updated on upon a change in the state of their morality.

Reference:

[HTU] http://deathnote.wikia.com/wiki/Rules_of_the_Death_Note

Notes:

* Correction credit to u/aeschenkarnos over at r/rational

