diff --git a/Makefile b/Makefile
index 80efdf4f7e..d58d0c9145 100644
--- a/Makefile
+++ b/Makefile
@@ -218,6 +218,7 @@ J191_6_OFILES_UT=\
        gen191/6/ut_repo.o \
        gen191/6/ut_rest.o \
        gen191/6/ut_seek.o \
+       gen191/6/ut_sift.o \
        gen191/6/ut_swab.o \
        gen191/6/ut_tack.o \
        gen191/6/ut_tock.o \
diff --git a/gen191/6/ut.c b/gen191/6/ut.c
index ba8bb3a74c..84d6895764 100644
--- a/gen191/6/ut.c
+++ b/gen191/6/ut.c
@@ -149,6 +149,7 @@
   extern u2_ho_jet j2_mcj(Pt6, ut, play)[];
   extern u2_ho_jet j2_mcj(Pt6, ut, rest)[];
   extern u2_ho_jet j2_mcj(Pt6, ut, seek)[];
+  extern u2_ho_jet j2_mcj(Pt6, ut, sift)[];
   extern u2_ho_jet j2_mcj(Pt6, ut, tack)[];
   extern u2_ho_jet j2_mcj(Pt6, ut, tock)[];
 
@@ -177,6 +178,7 @@
     { j2_sc(Pt6, ut, play), j2_mcj(Pt6, ut, play), 0, 0, u2_none },
     { j2_sc(Pt6, ut, rest), j2_mcj(Pt6, ut, rest), 0, 0, u2_none },
     { j2_sc(Pt6, ut, seek), j2_mcj(Pt6, ut, seek), 0, 0, u2_none },
+    { j2_sc(Pt6, ut, sift), j2_mcj(Pt6, ut, sift), 0, 0, u2_none },
     { j2_sc(Pt6, ut, tack), j2_mcj(Pt6, ut, tack), 0, 0, u2_none },
     { j2_sc(Pt6, ut, tock), j2_mcj(Pt6, ut, tock), 0, 0, u2_none },
     { }
diff --git a/gen191/6/ut_mint.c b/gen191/6/ut_mint.c
index 699c573f7d..550798da38 100644
--- a/gen191/6/ut_mint.c
+++ b/gen191/6/ut_mint.c
@@ -855,7 +855,8 @@
         u2_noun p_vos = u2_h(vos);
         u2_noun q_vos = u2_t(vos);
         u2_noun waz   = u2_bc(wir_r, _1, u2_rx(wir_r, p_vos));
-        u2_noun cig   = j2_mby(Pt6, cell)(wir_r, zur, p_vos);
+        u2_noun sif   = j2_mcy(Pt6, ut, sift)(wir_r, van, sut, zur);
+        u2_noun cig   = j2_mby(Pt6, cell)(wir_r, sif, p_vos);
         u2_noun ret;
 
         ret = u2_bc(wir_r,
@@ -864,6 +865,7 @@
 
         u2_rz(wir_r, waz);
         u2_rz(wir_r, zur);
+        u2_rz(wir_r, sif);
         u2_rz(wir_r, vos);
 
         return ret;
diff --git a/gen191/6/ut_sift.c b/gen191/6/ut_sift.c
new file mode 100644
index 0000000000..12b6860841
--- /dev/null
+++ b/gen191/6/ut_sift.c
@@ -0,0 +1,131 @@
+/* j/6/sift.c
+**
+** This file is in the public domain.
+*/
+#include "all.h"
+#include "../pit.h"
+
+/* boilerplate
+*/
+  u2_ho_jet 
+  j2_mcj(Pt6, ut, sift)[];
+
+  u2_noun                                                         //  transfer
+  j2_mc(Pt6, ut, sift)(u2_wire wir_r, 
+                       u2_noun cor)                               //  retain
+  {
+    u2_noun sut, ref, van;
+
+    if ( (u2_no == u2_mean(cor, u2_cv_sam, &ref, 
+                                u2_cv_con, &van, 
+                                0)) ||
+         (u2_none == (sut = u2_frag(u2_cv_sam, van))) )
+    {
+      return u2_bl_bail(wir_r, c3__fail);
+    } else {
+      return j2_mcy(Pt6, ut, sift)(wir_r, van, sut, ref);
+    }
+  }
+
+  u2_weak                                                         //  transfer
+  j2_mci(Pt6, ut, sift)(u2_wire wir_r,
+                        u2_noun van,                              //  retain
+                        u2_noun sut,                              //  retain 
+                        u2_noun ref)                              //  retain
+  {
+    u2_weak hoc = u2_ds_look(wir_r, van, "sift");
+
+    if ( u2_none == hoc ) {
+      c3_assert(!"register sift");
+      return u2_none;
+    } else {
+      u2_weak von = u2_rl_molt(wir_r, van, u2_cv_sam, u2_rx(wir_r, sut), 0);
+      u2_weak gat = u2_nk_soft(wir_r, von, hoc);
+      u2_weak cor = u2_rl_molt(wir_r, gat, u2_cv_sam, u2_rx(wir_r, ref), 0);
+
+      if ( (u2_none == j2_mcj(Pt6, ut, sift)[0].xip) ) {
+        u2_noun xip = u2_ds_find(wir_r, cor);
+     
+        //  c3_assert(u2_none != xip);
+        j2_mcj(Pt6, ut, sift)[0].xip = xip;
+      }
+      u2_rl_lose(wir_r, gat);
+      return cor;
+    }
+  }
+
+  u2_noun                                                         //  transfer
+  j2_mcy(Pt6, ut, sift)(u2_wire wir_r,
+                        u2_noun van,                              //  retain
+                        u2_noun sut,                              //  retain
+                        u2_noun ref)                              //  retain
+  {
+#if 0
+    u2_ho_jet *jet_j = &j2_mcj(Pt6, ut, sift)[0];
+
+    if ( (jet_j->sat_s & u2_jet_live) && !(jet_j->sat_s & u2_jet_test) ) {
+      if ( !(jet_j->sat_s & u2_jet_memo) ) {
+        return j2_mcx(Pt6, ut, sift)(wir_r, van, sut, ref);
+      }
+      else {
+        c3_m    fun_m = c3__sift;
+        u2_noun pro   = u2_rl_find_trel(wir_r, fun_m, sut, ref);
+
+        if ( u2_none != pro ) {
+          return pro;
+        }
+        else {
+          pro = j2_mcx(Pt6, ut, sift)(wir_r, van, sut, ref);
+
+          return u2_rl_save_trel(wir_r, fun_m, sut, ref, pro);
+        }
+      }
+      return pro;
+    } else 
+#else
+    {
+      u2_noun cor, pro;
+
+      cor = j2_mci(Pt6, ut, sift)(wir_r, van, sut, ref);
+
+      pro = u2_nk_soft(wir_r, u2k(cor), u2h(cor));
+      if ( u2_none == pro ) return u2_bl_bail(wir_r, c3__fail);
+
+      u2_rz(wir_r, cor);
+
+      return pro;
+#endif
+    }
+  }
+
+  u2_weak
+  j2_mck(Pt6, ut, sift)(u2_wire wir_r,
+                        u2_noun cor)
+  {
+    u2_noun sut, ref, van;
+
+    if ( (u2_no == u2_mean(cor, u2_cv_sam, &ref, 
+                                u2_cv_con, &van, 
+                                0)) ||
+         (u2_none == (sut = u2_frag(u2_cv_sam, van))) )
+    {
+      return u2_none;
+    } else {
+      return u2_rc
+        (wir_r, u2_rx(wir_r, sut), u2_rx(wir_r, ref));
+    }
+  }
+
+/* structures
+*/
+  u2_ho_jet 
+  j2_mcj(Pt6, ut, sift)[] = {
+    { ".2", c3__hevy, 
+        j2_mc(Pt6, ut, sift), 
+        Tier6_b_memo,
+        u2_none, u2_none,
+        j2_mck(Pt6, ut, sift), c3__sift
+    },
+    { }
+  };
+
diff --git a/gen191/pit.h b/gen191/pit.h
index 46636a08a8..eb9e4c12b8 100644
--- a/gen191/pit.h
+++ b/gen191/pit.h
@@ -635,6 +635,11 @@
                             u2_noun hep);                         //  retain
 
       u2_noun                                                     //  transfer
+      j2_mcy(Pt6, ut, sift)(u2_wire wir_r,
+                            u2_noun van,                          //  retain
+                            u2_noun sut,                          //  retain
+                            u2_noun ref);                         //  retain
+      u2_noun                                                     //  transfer
       j2_mcy(Pt6, ut, tack)(u2_wire wir_r,
                             u2_noun van,                          //  retain
                             u2_noun sut,                          //  retain