Sekai 🌐 πŸ—Ί

Sekai is the kanji for δΈ–η•Œ, meaning “the world”. That’s a great word because of the scale it designates.

Better Hugo ToC Fix

A JavaScript free way to improve default ToC


I applied a fix to Hugo’s ToC ten days ago.


To make the script non-render blocking, one has to place it in the footer. As a result, it takes about 0.2 seconds to remove the excess <ul> tag.


Thanks to Beej126’s Hugo template code, this site delivers table of contents processed by Hugo during GitLab’s continuous deployment.


Some Infinite Cardinality Identities

Working with infinite sets

Purpose This post aims at recapturing the main ideas of the formal proofs that I’ve read. It never tries to replace them. You may consult the references if you need any of them. Some notations Unless otherwise specified, all cardinalities here are infinite. Denote $\mathfrak{a} = \card{A}$, $\mathfrak{b} = \card{B}$ and $\mathfrak{i} = \card{I}$. Sum $\mathfrak{a} + \mathfrak{b} = \card{A \cup B}$ provided that $A \cap B =\varnothing$. Product $\mathfrak{a} \, \mathfrak{b} = \card{A \times B}$ Power $\mathfrak{a}^\mathfrak{i} = \card{A^I}$, where $A^I = \lbrace f \mid f: I \to A \rbrace$ denotes the set of functions from $I$ to $A$. [Read More]

Install Julia From Source

Custom built Julia from GitHub

Goal To get Julia installed as a normal user on RHEL 6. Motivation “Julia talks like Python but walks like C.” To do statistics more efficiently. The compiled binaries often contain install scripts which put files to shared folders under /usr. Consequently, they have to be run as sudo privileges. That drove me to start this lengthy Julia compilation. Installation Without sudo privileges, I’ve chosen to compile Julia from source. [Read More]
Linux  Julia 

My First RHEL Experience

Package installation as a normal user

Introduction This article records my errors and difficulties encountered on the first day I came across Red Hat Enterprise Linux 7 in my school’s laboratory, as a normal user without sudo privileges. The login screen was gdm, and the desktop environment was GNOME. IBus was used as the input engine. Packages installed The principal goal is to install tools that I usually use on RHEL without sudo permissions. To do so, I’ve downloaded the executable binaries or source code of these packages. [Read More]
Linux  RHEL 

$\pi$–$\lambda$ Theorem

Monotone Class Lemma

Statement Slogan version $$\sigma = \pi + \lambda$$ $\sigma$ $\pi$ $\lambda$ “sum” “product” “limit” universe nonempty universe complement complement countable union finite intersection disjoint countable union A $\sigma$-algebra is a $\pi$-system and a $\lambda$-system, and vice versa. Wiki version A $\lambda$-system is a synonym of a Dykin system. $$\mathcal{P} \subseteq \mathcal{D} \Longrightarrow \sigma(\mathcal{P}) \subseteq \mathcal{D}$$ [Read More]

Staticman API Hosting 2018

Step-by-step guide for free-hosting on Heroku

Goal To host an instance of Staticman v3 server on Heroku. This post involves server-side setup of the commenting system. If you simply want to have a taste of this system on GitLab, you may try my demo GitLab Page, and/or configure your GitLab repo (for your static web site) with my API instance. See the previous post in this series for a tutorial. I try to address some concerns about this API service in the introduction of this series to keep this page focused on the technical aspects of my customizations against staticman/dev branch. [Read More]

Copy File and Preserve Path

Two bash solutions

Background While making changes to a theme for a static site generator, I changed files under a Git submodule included in the repo for my blog. (e.g. themes/beautifulhugo) That’s ideal for local testing, but not for version control. As a result, I cloned the repo for the theme to a directory separate from the one for my bloge (say, ~/beautifulhugo), and commit the changes there, then performed a Git submodule update so as to make the workflow clean. [Read More]

Fix Hugo Table of Contents

Removal of wrapping HTML tag in JavaScript

Background (TL;DR) While setting up the new version of Staticman for my demo GitLab pages, I’ve read developers’ documentations, setup guide and some community blog posts so as to come up with my own guide. It’s originated and inspired from a variety of sources, and refined according to hours of testing. Consequently, despite the original intention to keep things simple, I’ve finally come up with a post with over a thousand words. [Read More]

Config GitLab Repo for Staticman

To keep focused on the technical setup, please refer to the introduction of this series for the reasons of choosing Staticman and GitLab. Goal To set up unauthenticated commenting system on GitLab pages. Demo GitLab Page with Staticman v3Built on 14/09/2018 This post aims at providing a walkthrough to the GitLab repo setup. If you want to host your own Staticman API instance, you may refer to the next post in this series. [Read More]

Welcome to static comments

Staticman Powered GitLab Pages

I put some “why” questions here so as to keep focus on the technical setup of the GitLab repo and the optional Staticman API server. Why static blogs instead of dynamic ones? quicker loading time better reliability (can handle more request) no database needed greater control on content, styles and layout Why static comments? allow feedback from visitors site owner owns the comment locally (unlike WordPress, Facebook, Disqus, etc) no remote database needed, so no need to worry server errors from third-party commenting services. [Read More]