Install cl-parse-number by entering the following commands in the terminal:
sudo apt update sudo apt install cl-parse-number
Description:
parse a string into one of the standard Common Lisp number types
parse-number accepts an arbitrary string and attempts to parse the string into one of the standard Common Lisp number types, if possible, or else parse-number signals an error of type invalid-number.
Homepage: http://www.cliki.net/parse-number
Version: 1.4-1
Section: universe/lisp