Installation instructions for Agda 2.6.1.1 on Linux.
====================================================

These instructions are for Ubuntu. Analogous instructions might work
on other Linux distributions. If you can, make sure that you have a
sufficiently recent version of Linux. For example, Ubuntu 20.04 comes
with Agda 2.6. Older versions of Ubuntu may come with older Agda
versions, which may or may not lead to problems.

1. Install Emacs using the package manager of your distribution.
   E.g., in Ubuntu, you can enter the following in the terminal. 

   sudo apt update
   sudo apt install emacs 

2. Install Agda using your package manager.
   E.g., in Ubuntu, you can enter the followings in the terminal.

   sudo apt install agda

   Perhaps you also need this, but with Ubuntu 20.10, this package is
   not needed:
   
   sudo apt install agda-mode

3. Create a ".emacs" file under your home directory and paste the
   following text to it.

   (load-file (let ((coding-system-for-read 'utf-8))
          (shell-command-to-string "agda-mode locate")))

4. Create an empty file called "nat.agda" and open it in emacs.
   Paste the following Agda code to the file.

   data Nat : Set where
     Z : Nat
     S : Nat -> Nat

   Notice that there is no color for the above Agda code after you
   pasted it.  Now type Ctrl-C, followed by Ctrl-L in Emacs. This will
   color the above Agda code. If you see the colored code,
   congratulation, you have managed to set up Agda!  If not, don't
   worry. Come to ask us for help.