diff --git a/lama-spec.pdf b/lama-spec.pdf
index 32d3cbc1f..75fcbf8f8 100644
Binary files a/lama-spec.pdf and b/lama-spec.pdf differ
diff --git a/spec/07.standard_library.tex b/spec/07.standard_library.tex
index 1f3f01129..1d9b5a6c3 100644
--- a/spec/07.standard_library.tex
+++ b/spec/07.standard_library.tex
@@ -347,7 +347,9 @@ fresh list if images in the same order.}
   "\lstinline|Some (v)|" otherwise, where "\lstinline|v|"~--- the first value to satisfy "\lstinline|f|".
 }
 
-\descr{\lstinline|fun flatten (l)|}{Flattens an arbitrary nesting of lists into a regular list. The order of elements is preserved in both senses.}
+\descr{\lstinline|fun flatten (l)|}{Flattens a list of lists into a regular list. The order of elements is preserved in both senses.}
+
+\descr{\lstinline|fun deepFlatten (l)|}{Flattens an arbitrary nesting of lists of \emph{boxed} values into a regular list. The order of elements is preserved in both senses.}
 
 \descr{\lstinline|fun zip (a, b)|}{Zips a pair of lists into the list of pairs. Does not work for lists of different lengths.}
 
diff --git a/src/stdpath.ml b/src/stdpath.ml
index fa0d92a24..f3cd19db9 100644
--- a/src/stdpath.ml
+++ b/src/stdpath.ml
@@ -1 +1 @@
-let path = "/home/db/.opam/4.08.1/share/Lama"
+let path = "/home/db/.opam/ocaml-system.4.07.1/share/Lama"
diff --git a/src/version.ml b/src/version.ml
index 3d9a2aff6..e5cfd5503 100644
--- a/src/version.ml
+++ b/src/version.ml
@@ -1 +1 @@
-let version = "Version 1.00, d06d9a250, Mon Sep 21 21:30:08 2020 +0300"
+let version = "Version 1.00, 4c736914d, Mon Sep 21 23:46:13 2020 +0300"
diff --git a/stdlib/List.lama b/stdlib/List.lama
index 4ed5f856e..15d7f76d4 100644
--- a/stdlib/List.lama
+++ b/stdlib/List.lama
@@ -84,6 +84,21 @@ public fun flatten (l) {
     curr [0] := new    
   }
 
+  iter (fun (x) {iter (append, x)}, l);
+  
+  res [1]
+}
+
+public fun deepFlatten (l) {
+  local res = [0, {}], curr = [res];
+
+  fun append (x) {
+    local new = x : {};
+    
+    curr [0][1] := new;
+    curr [0] := new    
+  }
+
   fun traverse (l) {
     case l of
       _ : _ -> iter (traverse, l)
diff --git a/stdlib/regression/orig/test06.log b/stdlib/regression/orig/test06.log
index c4ed9eda0..685f6aaab 100644
--- a/stdlib/regression/orig/test06.log
+++ b/stdlib/regression/orig/test06.log
@@ -1,4 +1,5 @@
 Flattening: 0
+Flattening: {0, 0, 0, 0}
 Flattening: 0
 Flattening: {1, 2, 3}
 Flattening: {1, 2, 3, 4, 5, 6, 7, 8, 9}
diff --git a/stdlib/regression/orig/test32.log b/stdlib/regression/orig/test32.log
new file mode 100644
index 000000000..898989cb5
--- /dev/null
+++ b/stdlib/regression/orig/test32.log
@@ -0,0 +1,2 @@
+Flattening: 0
+Flattening: {A, B, C, D}
diff --git a/stdlib/regression/test06.lama b/stdlib/regression/test06.lama
index b0117889f..e5ff34864 100644
--- a/stdlib/regression/test06.lama
+++ b/stdlib/regression/test06.lama
@@ -2,6 +2,7 @@ import List;
 import Array;
 
 printf ("Flattening: %s\n", flatten ({}).string);
+printf ("Flattening: %s\n", flatten ({{0}, {0, 0, 0}}).string);
 printf ("Flattening: %s\n", flatten ({{}, {}, {}}).string);
 printf ("Flattening: %s\n", flatten ({1, 2, 3} : {}).string);
 printf ("Flattening: %s\n", flatten ({{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}).string);
diff --git a/stdlib/regression/test32.lama b/stdlib/regression/test32.lama
new file mode 100644
index 000000000..138347f33
--- /dev/null
+++ b/stdlib/regression/test32.lama
@@ -0,0 +1,5 @@
+import List;
+import Array;
+
+printf ("Flattening: %s\n", deepFlatten ({}).string);
+printf ("Flattening: %s\n", deepFlatten ({{A}, {B, {C}, D}}).string)