Install xfonts-kapl by entering the following commands in the terminal:
sudo apt update sudo apt install xfonts-kapl
Description:
APL fonts for A+ development
The A+ programming language development environment requires these APL fonts to properly display A+ code in an XTerm, XEmacs or a web browser. They are not required to run an A+ program.
Version: 4.22.1-10
Section: universe/x11