diff --git a/debug.lsp b/debug.lsp
index 48ceff6..8790da6 100644
--- a/debug.lsp
+++ b/debug.lsp
@@ -1,5 +1,8 @@
-(print
-"ahoj"
-; tenhle komentar je problem
- )
-(print "sds")
\ No newline at end of file
+;; (print
+;; "ahoj"
+;; ; this comment is problem
+;; )
+;; (print "lisp")
+
+; (define l '(1 2 2 2 3 4 5 4 4 1 2 2 2 3 4 5 4 4 61 2 2 2 3 4 5 4 4 66)
+
diff --git a/tests/test.lsp b/tests/test.lsp
index 9463e7f..73329cd 100644
--- a/tests/test.lsp
+++ b/tests/test.lsp
@@ -154,4 +154,8 @@
 (print "list:" l)
 (print "uniq-ed list:" (uniq l))
 
+(define l '(1 2 (3 3 (4)) 5 6))
+(print "list:" l)
+(print "flatten-ed list:" (flatten l))
+
 (print "Test ends")
\ No newline at end of file
diff --git a/tmp/malformed_program.lsp b/tmp/malformed_program.lsp
index 73015fb..c9fe4f2 100644
--- a/tmp/malformed_program.lsp
+++ b/tmp/malformed_program.lsp
@@ -1,5 +1,5 @@
 (print
 "ahoj"
-; tenhle komentar je problem
+; this comment is problem
 )
-(print "sds")
\ No newline at end of file
+(print "lisp")
\ No newline at end of file