Problem Statement

A pangram is a sentence that contains all the letters of the English alphabet at least once. For example:   The quick brown fox jumps over the lazy dog.

Write a function or method to check a sentence to see if it is a   pangram   (or not)   and show its use.

Let's start with the solution:

(defun pangramp (s)
  (null (set-difference
          (loop for c from (char-code #\A) upto (char-code #\Z) collect (code-char c))
          (coerce (string-upcase s) 'list))))