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


go =>
   S1 = "The quick brown fox jumps over the lazy dog",
   S2 = "The slow brown fox jumps over the lazy dog",   
   println([S1, is_pangram(S1)]),
   println([S2, is_pangram(S2)]),
   nl,
   println("With missing chars:"),
   println([S1, is_pangram2(S1)]),
   println([S2, is_pangram2(S2)]),
   nl.
 
% Check if S is a pangram and get the missing chars
is_pangram(S) = P =>
   Lower = S.to_lowercase,
   Alpha = [chr(I+96) : I in 1..26],
   foreach(A in Alpha) membchk(A,Lower) end -> P = true ; P = false.
 
% Check if S is a pangram and get the missing chars (if any)
is_pangram2(S) = [pangram=cond(Missing==[],true,false),missing=Missing] =>
   Lower = S.to_lowercase,
   Missing = [A : A in [chr(I+96) : I in 1..26], not membchk(A,Lower)].