diff --git a/src/main.c b/src/main.c
index e548360..c8988ca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,7 +32,10 @@ static int main_loop(struct lexer_context *ctx, struct args_options *options,
 {
     int return_code = SUCCESS;
     // init parser
-    int parser_init();
+    if (!parser_init())
+    {
+        perror("parser initialization failed.");
+    }
 
     // Retrieve and build first AST
     struct ast *command_ast = get_ast(ctx);
diff --git a/src/parser/grammar.c b/src/parser/grammar.c
index 33551f5..b734c7b 100644
--- a/src/parser/grammar.c
+++ b/src/parser/grammar.c
@@ -186,7 +186,10 @@ struct ast *parse_input(struct lexer_context *ctx)
     struct token *token = PEEK_TOKEN();
 
     if (token->type == TOKEN_EOF)
-        return ast_create_list(NULL);
+    {
+        POP_TOKEN();
+        return ast_create_end();
+    }
 
     if (token->type == TOKEN_NEWLINE)
     {
diff --git a/src/parser/grammar_advanced.c b/src/parser/grammar_advanced.c
index aef3c27..faa2f5e 100644
--- a/src/parser/grammar_advanced.c
+++ b/src/parser/grammar_advanced.c
@@ -22,6 +22,9 @@ static enum ast_redir_type redir_tok_to_ast_type(enum token_type tok_type)
 
 struct ast *parse_redirection(struct lexer_context *ctx)
 {
+    (void)ctx;
+    return NULL;
+    /*
     struct token *token = PEEK_TOKEN();
     int io_number = -1;
     if (token->type == TOKEN_IONUMBER)
@@ -53,6 +56,7 @@ struct ast *parse_redirection(struct lexer_context *ctx)
     POP_TOKEN();
 
     return ast_create_redir(io_number, redir_type, target);
+    */
 }
 
 struct ast *parse_prefix(struct lexer_context *ctx)
diff --git a/src/parser/parser.c b/src/parser/parser.c
index b71867a..e5c5f94 100644
--- a/src/parser/parser.c
+++ b/src/parser/parser.c
@@ -25,6 +25,16 @@ bool parser_init(void)
     return true;
 }
 
+void parser_close(void)
+{
+    if (state != PARSER_STATE_READY)
+    {
+        perror("trying to close parser which was not opened");
+    }
+    state = PARSER_STATE_CLOSED;
+    // TODO close grammar
+}
+
 struct ast *get_ast(struct lexer_context *ctx)
 {
     if (ctx == NULL)
diff --git a/src/utils/Makefile.am b/src/utils/Makefile.am
index 65cc594..c2cf250 100644
--- a/src/utils/Makefile.am
+++ b/src/utils/Makefile.am
@@ -14,6 +14,9 @@ libutils_a_SOURCES =  \
 	ast/ast_redir.c \
 	ast/ast_void.c \
 	ast/ast_end.c \
+	ast/ast_word.c \
+	ast/ast_neg.c \
+	ast/ast_pipe.c \
 	args/args.c \
 	vars/vars.c
 
diff --git a/src/utils/ast/ast.h b/src/utils/ast/ast.h
index cbb5efc..334820b 100644
--- a/src/utils/ast/ast.h
+++ b/src/utils/ast/ast.h
@@ -11,6 +11,7 @@
 #include "ast_void.h"
 #include "ast_word.h"
 #include "ast_pipe.h"
+#include "ast_neg.h"
 
 /**
  * Prints the Graphviz DOT representation of the given AST to stdout.
diff --git a/src/utils/ast/ast_base.h b/src/utils/ast/ast_base.h
index 341b380..127dad7 100644
--- a/src/utils/ast/ast_base.h
+++ b/src/utils/ast/ast_base.h
@@ -29,6 +29,7 @@ struct ast
      * - struct ast_command* (AST_CMD)
      * - struct ast_and_or* (AST_AND_OR)
      * - struct ast_redir* (AST_REDIR)
+     * - and a lot more now...
      */
     void *data;
 };
diff --git a/src/utils/ast/ast_command.c b/src/utils/ast/ast_command.c
index 2b6bbf6..14904ae 100644
--- a/src/utils/ast/ast_command.c
+++ b/src/utils/ast/ast_command.c
@@ -18,7 +18,7 @@ struct ast *ast_create_command(struct list *command)
 
 struct ast_command *ast_get_command(struct ast *node)
 {
-    if (node == NULL || node->type == AST_CMD)
+    if (node == NULL || node->type != AST_CMD)
         return NULL;
     return (struct ast_command *)node->data;
 }
diff --git a/src/utils/ast/ast_neg.c b/src/utils/ast/ast_neg.c
index f5817fc..80dc4f3 100644
--- a/src/utils/ast/ast_neg.c
+++ b/src/utils/ast/ast_neg.c
@@ -4,7 +4,7 @@
 
 bool ast_is_neg(struct ast *node)
 {
-    return node != NULL && node->type == AST_REDIR;
+    return node != NULL && node->type == AST_NEG;
 }
 
 struct ast_neg *ast_get_neg(struct ast *node)
@@ -20,6 +20,8 @@ struct ast *ast_create_neg(bool negation, struct ast *child)
     if (!node)
         return NULL;
 
+    node->negation = negation;
+    node->child = child;
     return ast_create(AST_NEG, node);
 }
 
diff --git a/src/utils/ast/ast_word.c b/src/utils/ast/ast_word.c
index d798c77..957952c 100644
--- a/src/utils/ast/ast_word.c
+++ b/src/utils/ast/ast_word.c
@@ -1,5 +1,7 @@
+#define _POSIX_C_SOURCE 200809L
 #include "ast_word.h"
 
+#include <stdio.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>