<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Függvények</title>
</head>
<body>
<form action="" method="POST">
<input type="number" name="num1"> +
<input type="number" name="num2">
<button type="submit">Összead</button>
</form>
<p><?php echo $value?></p>
</body>
</html>