diff --git a/prelude/DATS/VT/strm000_vt.dats b/prelude/DATS/VT/strm000_vt.dats
index babf4a262..524c027df 100644
--- a/prelude/DATS/VT/strm000_vt.dats
+++ b/prelude/DATS/VT/strm000_vt.dats
@@ -38,6 +38,14 @@ Authoremail: gmhwxiATgmailDOTcom
 (* ****** ****** *)
 (* ****** ****** *)
 //
+#impltmp
+{ x0:vt }
+g_free//~xs
+<strm_vt(x0)>(xs) = $free(xs)
+//
+(* ****** ****** *)
+(* ****** ****** *)
+//
 (*
 HX-2024-07-17:
 Wed 17 Jul 2024 10:27:26 PM EDT
@@ -237,11 +245,43 @@ It is not harm to keep it here as a reference.
 #impltmp
 { x0:vt }
 gseq_filter0_lstrm
-<strm_vt(x0)><x0> = strm_vt_filter0<x0>(*void*)
+<strm_vt(x0)><x0> = strm_vt_filter0<x0>
 //
 (* ****** ****** *)
 (* ****** ****** *)
 //
+(*
+HX-2024-09-05:
+Thu 05 Sep 2024 07:59:10 PM EDT
+*)
+#impltmp
+<a>(*tmp*)
+strm_vt_concat0
+  ( xss ) =
+(
+  auxmain(xss)) where
+{
+fun auxmain(xss) = $llazy
+(
+case+ !xss of
+| ~
+strmcon_vt_nil() =>
+strmcon_vt_nil()
+| ~
+strmcon_vt_cons(xs1, xss) => !
+(
+ strm_vt_append00<a>(xs1, auxmain(xss)))
+)
+}(*where*)//end-of-[strm_vt_concat0(xss)]
+//
+(* ****** ****** *)
+(* ****** ****** *)
+//
+#impltmp
+<a>(*tmp*)
+strm_vt_append0 =
+strm_vt_append00<a>(*void*)
+//
 #impltmp
 <a>(*tmp*)
 strm_vt_append00
@@ -263,8 +303,8 @@ strmcon_vt_nil() => !ys
 | ~
 strmcon_vt_cons(x0, xs) =>
 strmcon_vt_cons(x0, auxmain(xs, ys))
-) (*case+*)
-} (*where*)//end-of(strm_vt_append00(xs,ys))
+)(*case+*)
+}(*where*)//end-of(strm_vt_append00(xs,ys))
 //
 (* ****** ****** *)
 (* ****** ****** *)
diff --git a/prelude/DATS/gseq002.dats b/prelude/DATS/gseq002.dats
index 3f302d719..9787373f8 100644
--- a/prelude/DATS/gseq002.dats
+++ b/prelude/DATS/gseq002.dats
@@ -216,6 +216,46 @@ x2rforall$test<x0><y0>(x0, y0) = rforall$test@(x0, y0)
 (* ****** ****** *)
 //
 (*
+HX-2024-09-05:
+Thu 05 Sep 2024 08:13:20 PM EDT
+*)
+#impltmp
+{ xs:t0
+, x0:t0
+, ys:t0
+, y0:t0 }
+gseq_strmize
+<
+gx2seq
+(xs,x0,ys,y0)><(x0,y0)>
+  (xsys) =
+let
+//
+#typedef
+xy = @(x0, y0)
+//
+val
+@(xs, ys) =
+x2tup_unmk(xsys)
+val xs = GSEQ_unmk(xs)
+and ys = GSEQ_unmk(ys)
+//
+in//let
+strm_vt_concat0<xy>
+(
+gseq_map_f1un_lstrm
+<xs><x0><strm_vt(xy)>
+(
+xs,
+lam(x0) =>
+gseq_map_f1un_lstrm<ys><y0><xy>(ys,lam(y0)=>(x0,y0)))
+)
+end//let//end-of-[gseq_strmize<gx2seq(...)><...>]
+//
+(* ****** ****** *)
+(* ****** ****** *)
+//
+(*
 HX-2024-08-05:
 Mon 05 Aug 2024 06:21:53 PM EDT
 *)
@@ -555,7 +595,7 @@ Sun 04 Aug 2024 07:26:14 AM EDT
 (*
 HX-2024-08-04:
 This one is BUGGY!!!
-Can you spot the cause :)
+Can you spot the SUBTLE cause :)
 #impltmp
 < xs:t0 >
 < x0:t0 >
@@ -572,7 +612,9 @@ forall$test<x0>(x0) =
 gseq_forall<ys><y0>(ys)) where
 {
 #impltmp
-forall$test<y0>(y0) = x2forall$test<x0><y0>(x0, y0)
+forall$test<y0>(y0) =
+(
+  x2forall$test<x0><y0>(x0, y0))
 }(*where*)
 }(*where*)//end-of-[gseq_x2forall(xs, ys)]
 *)
diff --git a/prelude/DATS/list000.dats b/prelude/DATS/list000.dats
index 37c86a0e3..fb524ed20 100644
--- a/prelude/DATS/list000.dats
+++ b/prelude/DATS/list000.dats
@@ -473,25 +473,70 @@ where
 < x0:t0 >
 list_make_t0up3(xs) =
 let
-val @(x0, x1, x2) = xs in//let
+val @(x0, x1, x2) = xs in
 (
   list_make_3val<x0>(x0, x1, x2))
 end//let//end-of-[list_make_t0up3]
 //
 (* ****** ****** *)
 //
+(*
 #impltmp
 < x0:t0 >
 list_make_t0up4 =
 list_make_gseq<t0up(x0,x0,x0,x0)><x0>
+*)
+#impltmp
+< x0:t0 >
+list_make_t0up4(xs) =
+let
+val
+@(x0, x1, x2, x3) = xs in
+(
+list_cons(x0,
+  list_make_3val<x0>(x1, x2, x3)))
+end//let//end-of-[list_make_t0up4(xs)]
+//
+(*
 #impltmp
 < x0:t0 >
 list_make_t0up5 =
 list_make_gseq<t0up(x0,x0,x0,x0,x0)><x0>
+*)
 #impltmp
 < x0:t0 >
-list_make_t0up5 =
+list_make_t0up5(xs) =
+let
+//
+val
+@(x0, x1, x2, x3, x4) = xs in
+(
+list_cons(x0,
+list_cons(x1,
+  list_make_3val<x0>(x2, x3, x4))))
+end//let//end-of-[list_make_t0up5(xs)]
+//
+(*
+#impltmp
+< x0:t0 >
+list_make_t0up6 =
 list_make_gseq<t0up(x0,x0,x0,x0,x0,x0)><x0>
+*)
+#impltmp
+< x0:t0 >
+list_make_t0up6(xs) =
+let
+//
+val
+@(x0, x1, x2, x3, x4, x5) = xs
+//
+in//let
+(
+list_cons(x0,
+list_cons(x1,
+list_cons(x2,
+  list_make_3val<x0>(x3, x4, x5)))))
+end//let//end-of-[list_make_t0up6(xs)]
 //
 (* ****** ****** *)
 (* ****** ****** *)
diff --git a/prelude/SATS/VT/strm000_vt.sats b/prelude/SATS/VT/strm000_vt.sats
index 3614e408b..0e6cb7dfd 100644
--- a/prelude/SATS/VT/strm000_vt.sats
+++ b/prelude/SATS/VT/strm000_vt.sats
@@ -77,6 +77,21 @@ strq_vt_length0
 //
 fun
 <x0:vt>
+strm_vt_concat0
+( xss
+: strm_vt
+( strm_vt(x0) )): strm_vt(x0)
+//
+(* ****** ****** *)
+(* ****** ****** *)
+//
+fun
+<x0:vt>
+strm_vt_append0
+( xs: strm_vt(x0)
+, ys: strm_vt(x0)): strm_vt(x0)
+fun
+<x0:vt>
 strm_vt_append00
 ( xs: strm_vt(x0)
 , ys: strm_vt(x0)): strm_vt(x0)
diff --git a/prelude/TEST/CATS/JS/Makefile_jsemit b/prelude/TEST/CATS/JS/Makefile_jsemit
index 3a55360ce..f1194fefa 100644
--- a/prelude/TEST/CATS/JS/Makefile_jsemit
+++ b/prelude/TEST/CATS/JS/Makefile_jsemit
@@ -163,7 +163,7 @@ test07:: ; \
 $(CAT) $(SRCGEN2_XSHARED)/xats2js_prelude.js >> $@_out.js
 ############
 test07:: \
-test07_gcls000.dats; \
+test07_gseq000.dats; \
 $(NODE) --stack-size=4096 $(SRCGEN2_XATS2JS) $< >> $@_out.js
 ########################################################################
 ########################################################################
diff --git a/prelude/TEST/CATS/JS/test07_gcls000.dats b/prelude/TEST/CATS/JS/test07_gseq000.dats
similarity index 75%
rename from prelude/TEST/CATS/JS/test07_gcls000.dats
rename to prelude/TEST/CATS/JS/test07_gseq000.dats
index 10cb19161..2d0c8e8a1 100644
--- a/prelude/TEST/CATS/JS/test07_gcls000.dats
+++ b/prelude/TEST/CATS/JS/test07_gseq000.dats
@@ -25,6 +25,10 @@ For testing prelude/JS!
 (* ****** ****** *)
 (* ****** ****** *)
 //
+(*
+HX-2024-09-05:
+Already defined in gseq002
+*)
 #define
 GZ2SEQ(xs, ys) =
 GSEQ_z2make(GSEQ(xs), GSEQ(ys))
@@ -36,18 +40,32 @@ GSEQ_x2make(GSEQ(xs), GSEQ(ys))
 (* ****** ****** *)
 //
 val xs = list@(1, 2, 3)
-val ys = list@(10,20,30)
+val ys = list@(10,20,30,40)
 val () = prints("xs = ", xs, "\n")
 val () = prints("ys = ", ys, "\n")
 //
 (* ****** ****** *)
-//
-val ztup = GZ2SEQ(xs, ys)
-val zxys = rlistize(ztup)
+///
+val ztup =
+GZ2SEQ(xs, ys)
 val (  ) =
 prints("ztup = ", ztup, "\n")
+//
+val zxys = listize(ztup)
 val (  ) =
-print1s("rlistize(ztup) = ", zxys, "\n")
+print1s("listize(ztup) = ", zxys, "\n")
+//
+(* ****** ****** *)
+//
+val xztup =
+GSEQ_x2make
+(GSEQ(xs), ztup)
+val (   ) =
+prints("xztup = ", xztup, "\n")
+//
+val xzxys = listize(xztup)
+val (   ) =
+print1s("listize(xztup) = ", xzxys, "\n")
 //
 (* ****** ****** *)
 (* ****** ****** *)
diff --git a/srcgen1/prelude/SATS/xunimpl.sats b/srcgen1/prelude/SATS/xunimpl.sats
index 8721e2e48..0858a5598 100644
--- a/srcgen1/prelude/SATS/xunimpl.sats
+++ b/srcgen1/prelude/SATS/xunimpl.sats
@@ -1592,6 +1592,19 @@ fun
 list_make_t0up3
 (tup: t0up(x0,x0,x0)): list(x0,3)
 //
+fun
+<x0:t0>
+list_make_t0up4
+(tup: t0up(x0,x0,x0,x0)): list(x0,4)
+fun
+<x0:t0>
+list_make_t0up5
+(tup: t0up(x0,x0,x0,x0,x0)): list(x0,5)
+fun
+<x0:t0>
+list_make_t0up6
+(tup: t0up(x0,x0,x0,x0,x0,x0)): list(x0,6)
+//
 (* ****** ****** *)
 (* ****** ****** *)
 //
diff --git a/xatslib/githwxi/TEST/CATS/JS/test99_mydiary.dats b/xatslib/githwxi/TEST/CATS/JS/test99_mydiary.dats
index 56481c1da..3ac4f01b7 100644
--- a/xatslib/githwxi/TEST/CATS/JS/test99_mydiary.dats
+++ b/xatslib/githwxi/TEST/CATS/JS/test99_mydiary.dats
@@ -232,19 +232,6 @@ val () = prints("\n")
 val rys = rlistize(GSEQ(ys))
 val ( ) = print1s("rys = ", rys, "\n")
 ////
-val rxys =
-rlistize(GZ2SEQ(xs, ys))
-val ( ) =
-print1s("rlistize(GSEQ_z2make(GSEQ(xs), GSEQ(ys))) = ", rxys, "\n")
-//
-val xys =
-listize(GX2SEQ(xs, ys))
-val ( ) =
-print1s("listize(GSEQ_x2make(GSEQ(xs), GSEQ(ys))) = ", xys, "\n")
-val rxys =
-rlistize(GX2SEQ(xs, ys))
-val ( ) =
-print1s("rlistize(GSEQ_x2make(GSEQ(xs), GSEQ(ys))) = ", rxys, "\n")
 //
 (* ****** ****** *)
 (* ****** ****** *)