Pangram checker

You are encouraged to solve this task according to the task description, using any language you may know.
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.



Task

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



Related tasks

   determine if a string has all the same characters
   determine if a string has all unique characters


def is_pangram:
  explode
  | map( if 65 <= . and . <= 90 then . + 32 # uppercase
         elif 97 <= . and . <= 122 then .   # lowercase
         else empty
         end )
  | unique
  | length == 26;
 
# Example:
"The quick brown fox jumps over the lazy dog" | is_pangram