ProcISBN:=proc()

local i, isbn, teste;

begin
	input("Indique o ISBN da forma [a,b,c,...] ",isbn):
	isbnArray:=array(1..10,isbn);
	teste:=0;
	for i from 10 downto 1 do
		teste:=teste+(11-i)*isbnArray[i]
	end_for: 
	if (teste mod 11 = 0) then print("O ISBN esta' correcto")
	else print(" O ISBN esta' incorrecto"):
	end_if:
end_proc: