prime numbers

program prime_numbers;

type TList = array of word;

function isPrime(n : word) : Boolean;
var i : word;
begin
    isPrime := true;
    for i in [2..n div 2] do
        if n mod i = 0 then begin
            isPrime := false;
            break;
        end;
end;

function listNPrimes(n : word) : TList;
var i, count : word;
begin
    SetLength(listNPrimes, 1);
    if n >= 1 then begin
        count := 0;
        listNPrimes[0] := 2;
        i := 3;
        while (count < n) do begin
            if isPrime(i) then begin
                SetLength(listNPrimes, length(listNPrimes)+1);
                listNPrimes[length(listNPrimes)-1] := i;
                inc(count);
            end;
            inc(i);
        end;
    end else listNPrimes[0] := 0;
end;

function listPrimesTill(n : word) : TList;
var i : word = 3;
begin
    SetLength(listPrimesTill, 1);
    if n >= 2 then begin
        listPrimesTill[0] := 2;
        while not(i >= n) do begin
            if isPrime(i) then begin
                SetLength(listPrimesTill, length(listPrimesTill)+1);
                listPrimesTill[length(listPrimesTill)-1] := i;
            end;
            inc(i);
        end;
    end else listPrimesTill[0] := 0;
end;

var elem : integer;
begin
    for elem in listNPrimes(10) do write(elem,', '); writeln;
    for elem in listPrimesTill(40) do write(elem,', ');
    readln;
end.