Errata for Programming Bitcoin - Jimmy Song( @jimmysong )、O'Reilly Media( @OReillyMedia ) - Elliptic Curves - Point Addition for When x1≠x2 - Deriving the Point Addition Formula - submitted

Programming Bitcoin
Learn How to Program Bitcoin from Scratch
楽天ブックス(Kobo) 紀伊國屋書店(Kinoppy)

読書環境

• Kindle(白黒)
• iPad Pro 10.5 + Kindle(カラー)
• 紙

Programming Bitcoin: Learn How to Program Bitcoin from Scratch (Jimmy Song(著)、O'Reilly Media)のChapter 2(Elliptic Curves)に誤植(？)(typo)を発見。

ということで、報告してみた。

Point Addition for When x1≠x2のDeriving the Point Addition Formula(36)

$\begin{array}{}{x}_3-s^2{x}^2+\left(a+2s^2{x}_1-2sy\sim \; <!--\; tilde\; operator\; -->1\sim \; <!--\; tilde\; operator\; -->\right)x+\\ b-s^2{x}^2+2sx\sim \; <!--\; tilde\; operator\; -->1\sim \; <!--\; tilde\; operator\; -->y_1-y_1^2=0\end{array}$

ではなく、

$\begin{array}{}{x}_3-s^2{x}^2+\left(a+2s^2{x}_1-2s{y}_1\right)x+\\ b-s^2{x}^2+2s{x}_1{y}_1-y_1^2=0\end{array}$

添字が何故か波「~」になっている。