Почему появляется ошибка Fatal error: Cannot redeclare exc_post() когда if ($_SESSION['filter1'] == '' )?

Я пишу плагин фильтраций тегов для wordpress но почему то у меня появляется ошибка
Fatal error: Cannot redeclare exc_post() (previously declared in C:\xampp\htdocs\wor\wp-content\plugins\GOG11\GOG11.php:64) in C:\xampp\htdocs\wor\wp-content\plugins\GOG11\GOG11.php on line 141
На строке
if ($_SESSION['filter2'] == ''){
И самое любопытное то что на точно такой же строке только
if ($_SESSION['filter1'] == ''){
Ошибки нету
И она возникает только когда ['filter2'] == '' при всех остальных значениях все работает нормально
Если вместо пропуска я указываю 1 то ошибка появляется уже на filter4 перескакивая filter3

Вот весь код плагина

session_start();
		  if ($_POST['filter1']){	
		$_SESSION['filter1'] = $_POST['filter1'];
		}
		
		  if ($_POST['filter2']){	
		$_SESSION['filter2'] = $_POST['filter2'];
		}
		
		 add_shortcode ('wp-r_dop_filter','A2'); 
		function A2(){
			  
			   
			   
			   
			$R1='
		 
	<form method="POST" >
	<p>Option filter</p>

	<p>Filter 1</p>
	level 1:  <input type="radio" name="filter1" value="1"' . ($_SESSION["filter1"] == 1 ? 'checked' : '') . '/> 
	level 2:  <input type="radio" name="filter1" value="2"' . ($_SESSION["filter1"] == 2 ? 'checked' : '') . '/> 
	 
	<p>Filter 2</p>
	level 1:  <input type="radio" name="filter2" value="1"' .  ($_SESSION["filter2"] == 1 ? 'checked' : '') .  '/> 
	level 2:  <input type="radio" name="filter2" value="2"' .  ($_SESSION["filter2"] == 2 ? 'checked' : '') .  '/> 
	 
	 

	<p><input type="submit" value="User"></p>
	</form>
		   ';

		   return  $R1;
		}
		
		
		
		
		
		
		
		
		
		
		
	if ($_SESSION['filter1'] == ''){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter1_query_lv0 ) {
		if ($filter1_query_lv0->is_category || ($filter1_query_lv0->is_home || ($filter1_query_lv0->is_feed) || ($filter1_query_lv0->is_tag)))  
		{
	$filter1_way_lv0_1 = plugin_dir_url( __FILE__ );  
	$filter1_way_lv0_2 = file_get_contents( $filter1_way_lv0_1 . 'filter1/level_1.txt');   
	$filter1_way_lv0_3 = explode (",", $filter1_way_lv0_2);  

			
			
			$filter1_query_lv0->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter1_way_lv0_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter1_query_lv0;
	}
	}
	else if ($_SESSION['filter1'] == 1){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter1_query_lv1) {
		if ($filter1_query_lv1->is_category || ($filter1_query_lv1->is_home || ($filter1_query_lv1->is_feed) || ($filter1_query_lv1->is_tag)))  
		{
	$filter1_way_lv1_1 = plugin_dir_url( __FILE__ );  
	$filter1_way_lv1_2 = file_get_contents( $filter1_way_lv1_1 . 'filter1/level_1.txt');   
	$filter1_way_lv1_3 = explode (",", $filter1_way_lv1_2);  

			
			
			$filter1_query_lv1->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter1_way_lv1_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter1_query_lv1;
	}

	}
	else if ($_SESSION['filter1'] == 2){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter1_query_lv2) {
		if ($filter1_query_lv2->is_category || ($filter1_query_lv2->is_home || ($filter1_query_lv2->is_feed) || ($filter1_query_lv2->is_tag)))  
		{
	$filter1_way_lv2_1 = plugin_dir_url( __FILE__ );  
	$filter1_way_lv2_2 = file_get_contents( $filter1_way_lv2_1 . 'filter1/level_2.txt');   
	$filter1_way_lv2_3 = explode (",", $filter1_way_lv2_2);  

			
			
			$filter1_query_lv2->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter1_way_lv2_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter1_query_lv2;
	}

	}	
			
		

	if ($_SESSION['filter2'] == 1){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter2_query_lv0) {
		if ($filter2_query_lv0->is_category || ($filter2_query_lv0->is_home || ($filter2_query_lv0->is_feed) || ($filter2_query_lv0->is_tag)))  
		{
	$filter2_way_lv0_1 = plugin_dir_url( __FILE__ );  
	$filter2_way_lv0_2 = file_get_contents( $filter2_way_lv0_1 . 'filter2/level_1.txt');   
	$filter2_way_lv0_3 = explode (",", $filter2_way_lv0_2);  

			
			
			$filter2_query_lv0->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter2_way_lv0_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter2_query_lv0;
	}
	}
	else if ($_SESSION['filter2'] == 2){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter2_query_lv1) {
		if ($filter2_query_lv1->is_category || ($filter2_query_lv1->is_home || ($filter2_query_lv1->is_feed) || ($filter2_query_lv1->is_tag)))  
		{
	$filter2_way_lv1_1 = plugin_dir_url( __FILE__ );  
	$filter2_way_lv1_2 = file_get_contents( $filter2_way_lv1_1 . 'filter2/level_1.txt');   
	$filter2_way_lv1_3 = explode (",", $filter2_way_lv1_2);  

			
			
			$filter2_query_lv1->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter2_way_lv1_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter2_query_lv1;
	}

	}
	else if ($_SESSION['filter2'] == ''){
		
	add_filter('pre_get_posts','exc_post'); 
	function exc_post($filter2_query_lv2) {
		if ($filter2_query_lv2->is_category || ($filter2_query_lv2->is_home || ($filter2_query_lv2->is_feed) || ($filter2_query_lv2->is_tag)))  
		{
	$filter2_way_lv2_1 = plugin_dir_url( __FILE__ );  
	$filter2_way_lv2_2 = file_get_contents( $filter2_way_lv2_1 . 'filter2/level_2.txt');   
	$filter2_way_lv2_3 = explode (",", $filter2_way_lv2_2);  

			
			
			$filter2_query_lv2->set('tax_query', array(  
				array(
					'taxonomy' => 'post_tag',
					'field' => 'slug',
					'terms' =>  $filter2_way_lv2_3,  
					'operator' => 'NOT IN'
				)
			));
		}
		return $filter2_query_lv2;
	}

	}

Код был упрощен