diff --git a/.gitignore b/.gitignore
index 2168f0fd5..0a16f88aa 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@ test-peek-file-reader
 test-parse-trie
 test-lrec
 test-multiple-containers
+test-mlhmmv
 test-lrec-evaluators
 test_lrec_evaluators
 test-join-bucket-keeper
@@ -69,6 +70,7 @@ test_lrec
 test_mlrutil
 test_mlrregex
 test_multiple_containers
+test_mlhmmv
 test_parse_trie
 test_peek_file_reader
 test_string_builder
diff --git a/c/Makefile.no-autoconfig b/c/Makefile.no-autoconfig
index d6ce41081..687b58c00 100644
--- a/c/Makefile.no-autoconfig
+++ b/c/Makefile.no-autoconfig
@@ -140,7 +140,7 @@ TEST_MLHMMV_SRCS = \
   lib/mlrutil.c \
   lib/mlr_globals.c \
   containers/mlhmmv.c \
-  containers/sllv.c \
+  containers/sllmv.c \
   unit_test/test_mlhmmv.c
 
 TEST_MLRUTIL_SRCS = \
diff --git a/c/containers/Makefile.am b/c/containers/Makefile.am
index 1c192b982..234e48474 100644
--- a/c/containers/Makefile.am
+++ b/c/containers/Makefile.am
@@ -41,6 +41,8 @@ libcontainers_la_SOURCES=	\
 			slls.h \
 			sllv.c \
 			sllv.h \
+			sllmv.c \
+			sllmv.h \
 			top_keeper.c \
 			top_keeper.h
 libcontainers_la_LIBADD=	\
diff --git a/c/containers/mlhmmv.c b/c/containers/mlhmmv.c
index b69e5d660..a1ff685db 100644
--- a/c/containers/mlhmmv.c
+++ b/c/containers/mlhmmv.c
@@ -140,11 +140,13 @@ static void mlhmmv_level_free(mlhmmv_level_t* plevel) {
 //}
 
 // ----------------------------------------------------------------
-void mlhmmv_put(mlhmmv_t* pmap, sllv_t* pmkeys, mv_t* pvalue) {
+void mlhmmv_put(mlhmmv_t* pmap, sllmv_t* pmkeys, mv_t* pvalue) {
+}
+
+// level-put material:
 //	if ((pmap->num_occupied + pmap->num_freed) >= (pmap->array_length*LOAD_FACTOR))
 //		mlhmmv_enlarge(pmap);
 //	return mlhmmv_put_no_enlarge(pmap, key, pvvalue, free_flags);
-}
 
 //static void* mlhmmv_put_no_enlarge(mlhmmv_t* pmap, slls_t* key, void* pvvalue, char free_flags) {
 //	int index = mlhmmv_find_index_for_key(pmap, key);
@@ -191,7 +193,7 @@ void mlhmmv_put(mlhmmv_t* pmap, sllv_t* pmkeys, mv_t* pvalue) {
 //}
 
 // ----------------------------------------------------------------
-mv_t* mlhmmv_get(mlhmmv_t* pmap, sllv_t* pmvkeys) {
+mv_t* mlhmmv_get(mlhmmv_t* pmap, sllmv_t* pmvkeys) {
 //	int index = mlhmmv_find_index_for_key(pmap, key);
 //	mlhmmv_entry_t* pe = &pmap->entries[index];
 //
@@ -207,7 +209,7 @@ mv_t* mlhmmv_get(mlhmmv_t* pmap, sllv_t* pmvkeys) {
 }
 
 // ----------------------------------------------------------------
-int mlhmmv_has_keys(mlhmmv_t* pmap, sllv_t* pmvkeys) {
+int mlhmmv_has_keys(mlhmmv_t* pmap, sllmv_t* pmvkeys) {
 //	int index = mlhmmv_find_index_for_key(pmap, key);
 //
 //	if (pmap->states[index] == OCCUPIED)
@@ -306,3 +308,11 @@ int mlhmmv_has_keys(mlhmmv_t* pmap, sllv_t* pmvkeys) {
 //			pe->ideal_index, key_string, value_string);
 //	}
 //}
+
+// ----------------------------------------------------------------
+mlhmmv_value_t* mlhmmv_value_from_mv(mv_t* pmv) {
+	mlhmmv_value_t* pvalue = mlr_malloc_or_die(sizeof(mlhmmv_value_t));
+	pvalue->type = MLHMMV_VALUE_TYPE_TERMINAL;
+	pvalue->u.mlrval = mv_copy(pmv);
+	return pvalue;
+}
diff --git a/c/containers/mlhmmv.h b/c/containers/mlhmmv.h
index 84553ec67..a6d894e42 100644
--- a/c/containers/mlhmmv.h
+++ b/c/containers/mlhmmv.h
@@ -17,7 +17,7 @@
 #define MLHMMV_H
 
 #include "containers/mlrval.h"
-#include "containers/sllv.h"
+#include "containers/sllmv.h"
 
 #define MLHMMV_VALUE_TYPE_TERMINAL     0xabcd
 #define MLHMMV_VALUE_TYPE_NON_TERMINAL 0xfedc
@@ -61,9 +61,11 @@ typedef struct _mlhmmv_t {
 mlhmmv_t* mlhmmv_alloc();
 void  mlhmmv_free(mlhmmv_t* pmap);
 // pmkeys is a list of mlhmmv_value_t
-void  mlhmmv_put(mlhmmv_t* pmap, sllv_t* pmvkeys, mv_t* pvalue);
-mv_t* mlhmmv_get(mlhmmv_t* pmap, sllv_t* pmvkeys);
-int   mlhmmv_has_keys(mlhmmv_t* pmap, sllv_t* pmvkeys);
+void  mlhmmv_put(mlhmmv_t* pmap, sllmv_t* pmvkeys, mv_t* pvalue);
+mv_t* mlhmmv_get(mlhmmv_t* pmap, sllmv_t* pmvkeys);
+int   mlhmmv_has_keys(mlhmmv_t* pmap, sllmv_t* pmvkeys);
+
+mlhmmv_value_t* mlhmmv_value_from_mv(mv_t* pmv);
 
 //// Unit-test hook
 //int mlhmmv_check_counts(mlhmmv_t* pmap);
diff --git a/c/containers/mlrval.h b/c/containers/mlrval.h
index 294d19fdf..9c3595c6b 100644
--- a/c/containers/mlrval.h
+++ b/c/containers/mlrval.h
@@ -149,6 +149,12 @@ static inline mv_t mv_copy(mv_t* pval) {
 	}
 }
 
+static inline mv_t* mv_alloc_copy(mv_t* pold) {
+	mv_t* pnew = mlr_malloc_or_die(sizeof(mv_t));
+	*pnew = mv_copy(pold);
+	return pnew;
+}
+
 // ----------------------------------------------------------------
 static inline int mv_is_numeric(mv_t* pval) {
 	return pval->type == MT_INT || pval->type == MT_FLOAT;
diff --git a/c/containers/sllmv.c b/c/containers/sllmv.c
new file mode 100644
index 000000000..34f398a2b
--- /dev/null
+++ b/c/containers/sllmv.c
@@ -0,0 +1,67 @@
+#include "lib/mlrutil.h"
+#include "containers/sllmv.h"
+
+// ----------------------------------------------------------------
+sllmv_t* sllmv_alloc() {
+	sllmv_t* plist = mlr_malloc_or_die(sizeof(sllmv_t));
+	plist->phead  = NULL;
+	plist->ptail  = NULL;
+	plist->length = 0;
+	return plist;
+}
+
+// ----------------------------------------------------------------
+void sllmv_free(sllmv_t* plist) {
+	if (plist == NULL)
+		return;
+	sllmve_t* pnode = plist->phead;
+	while (pnode != NULL) {
+		sllmve_t* pdel = pnode;
+		pnode = pnode->pnext;
+		mv_free(pdel->pvalue);
+		free(pdel);
+	}
+	plist->phead  = NULL;
+	plist->ptail  = 0;
+	plist->length = 0;
+
+	free(plist);
+}
+
+// ----------------------------------------------------------------
+void sllmv_add(sllmv_t* plist, mv_t* pvalue) {
+	sllmve_t* pnode = mlr_malloc_or_die(sizeof(sllmve_t));
+	pnode->pvalue = mv_alloc_copy(pvalue);
+	if (plist->ptail == NULL) {
+		pnode->pnext = NULL;
+		plist->phead = pnode;
+		plist->ptail = pnode;
+	} else {
+		pnode->pnext = NULL;
+		plist->ptail->pnext = pnode;
+		plist->ptail = pnode;
+	}
+	plist->length++;
+}
+
+// ----------------------------------------------------------------
+sllmv_t* sllmv_single(mv_t* pvalue) {
+	sllmv_t* psllmv = sllmv_alloc();
+	sllmv_add(psllmv, pvalue);
+	return psllmv;
+}
+
+sllmv_t* sllmv_double(mv_t* pvalue1, mv_t* pvalue2) {
+	sllmv_t* psllmv = sllmv_alloc();
+	sllmv_add(psllmv, pvalue1);
+	sllmv_add(psllmv, pvalue2);
+	return psllmv;
+}
+
+sllmv_t* sllmv_triple(mv_t* pvalue1, mv_t* pvalue2, mv_t* pvalue3) {
+	sllmv_t* psllmv = sllmv_alloc();
+	sllmv_add(psllmv, pvalue1);
+	sllmv_add(psllmv, pvalue2);
+	sllmv_add(psllmv, pvalue3);
+	return psllmv;
+}
diff --git a/c/containers/sllmv.h b/c/containers/sllmv.h
new file mode 100644
index 000000000..d55d01c8f
--- /dev/null
+++ b/c/containers/sllmv.h
@@ -0,0 +1,31 @@
+// ================================================================
+// Singly-linked list of mlrval, with tail for append.
+// Everything is copied; nothing is referenced.
+// ================================================================
+
+#ifndef SLLMV_H
+#define SLLMV_H
+
+#include "mlrval.h"
+
+typedef struct _sllmve_t {
+	mv_t* pvalue;
+	struct _sllmve_t *pnext;
+} sllmve_t;
+
+typedef struct _sllmv_t {
+	sllmve_t *phead;
+	sllmve_t *ptail;
+	int length;
+} sllmv_t;
+
+sllmv_t* sllmv_alloc();
+void     sllmv_free(sllmv_t* plist);
+void     sllmv_add(sllmv_t* plist, mv_t* pvalue);
+
+sllmv_t* sllmv_single(mv_t* pvalue);
+sllmv_t* sllmv_double(mv_t* pvalue1, mv_t* pvalue2);
+sllmv_t* sllmv_triple(mv_t* pvalue1, mv_t* pvalue2, mv_t* pvalue3);
+
+#endif // SLLMV_H
+
diff --git a/c/unit_test/test_mlhmmv.c b/c/unit_test/test_mlhmmv.c
index 314a70f4a..417c2ef5c 100644
--- a/c/unit_test/test_mlhmmv.c
+++ b/c/unit_test/test_mlhmmv.c
@@ -13,6 +13,18 @@ int assertions_failed = 0;
 static char* test_stub() {
 	mu_assert_lf(0 == 0);
 
+	mlhmmv_t* pmap = mlhmmv_alloc();
+
+	mv_t key = mv_from_int(3LL);
+	sllmv_t* pmkeys = sllmv_single(&key);
+	mv_t value = mv_from_int(4LL);
+
+	mlhmmv_put(pmap, pmkeys, &value);
+
+	sllmv_free(pmkeys);
+
+	mlhmmv_free(pmap);
+
 	return NULL;
 }