diff --git a/testcases/insert_fn.mux b/testcases/insert_fn.mux
index 3d29ed5cf..b868990ab 100644
--- a/testcases/insert_fn.mux
+++ b/testcases/insert_fn.mux
@@ -20,11 +20,11 @@
 &tr.tc001 test_insert_fn=
   @if strmatch(
         setr(0,sha1(
-            insert(This is a test, 4, new)
-            [insert(Yet@Another@List, 3, Funk, @)]
+            [insert(This is a test, 4, new)]
+            [insert(Yet@Another@List, 3, Funky, @)]
           )
         ),
-        80194573F0E288397A859CD3A27CCF1FD922C8DB
+        406626B7163831461CDED124D892909E9E351FCB
       )=
   {
     @log smoke=TC001: Help file examples. Succeeded.
@@ -39,7 +39,7 @@
 &tr.tc002 test_insert_fn=
   @if strmatch(
         setr(0,sha1(
-            iter(0 1 2,## [insert(,##,Pear,|)])
+            [iter(0 1 2,## [insert(,##,Pear,|)])]
           )
         ),
         6A543151C6BDF80889FEAF3A53079DE952657E2A
@@ -57,12 +57,12 @@
 &tr.tc003 test_insert_fn=
   @if strmatch(
         setr(0,sha1(
-            iter(0 1 2 3,## [insert(|,##,Pear,|)])
-            iter(0 1 2 3 4,## [insert(||,##,Pear,|)])
-            iter(0 1 2 3 4 5,## [insert(|||,##,Pear,|)])
+            [iter(0 1 2 3,## [insert(|,##,Pear,|)])]
+            [iter(0 1 2 3 4,## [insert(||,##,Pear,|)])]
+            [iter(0 1 2 3 4 5,## [insert(|||,##,Pear,|)])]
           )
         ),
-        86316ADB7ADA940BCB55F7EE8BF4DE5E0852D34C
+        7CEB5283E8F723EF34A3468AE1CAD76D36517DCF
       )=
   {
     @log smoke=TC003: Non-empty lists, ASCII, positive positions. Succeeded.
@@ -77,7 +77,7 @@
 &tr.tc004 test_insert_fn=
   @if strmatch(
         setr(0,sha1(
-            iter(-2 -1,## [insert(,##,Pear,|)])
+            [iter(-2 -1,## [insert(,##,Pear,|)])]
           )
         ),
         FF317BAF06BA80EED00C1E604E5A94C16EADAA8F
@@ -95,12 +95,12 @@
 &tr.tc005 test_insert_fn=
   @if strmatch(
         setr(0,sha1(
-            iter(-3 -2 -1,## [insert(|,##,Pear,|)])
-            iter(-4 -3 -2 -1,## [insert(||,##,Pear,|)])
-            iter(-5 -4 -3 -2 -1,## [insert(|||,##,Pear,|)])
+            [iter(-3 -2 -1,## [insert(|,##,Pear,|)])]
+            [iter(-4 -3 -2 -1,## [insert(||,##,Pear,|)])]
+            [iter(-5 -4 -3 -2 -1,## [insert(|||,##,Pear,|)])]
           )
         ),
-        AA1255843386F29403032C2A238745291C562B90
+        377189E5484C2F769375C40A0540080FF649CE2F
       )=
   {
     @log smoke=TC005: Non-empty lists, ASCII, negative positions. Succeeded.;
diff --git a/testcases/replace_fn.mux b/testcases/replace_fn.mux
new file mode 100644
index 000000000..0c9804e8a
--- /dev/null
+++ b/testcases/replace_fn.mux
@@ -0,0 +1,121 @@
+#
+# replace_fn.mux - Test Cases for replace().
+#
+# Strategy: Exercise color and UTF-8 in combination with replace() behaviors.
+#
+@create test_replace_fn
+-
+@set test_replace_fn=INHERIT QUIET
+-
+#
+# Beginning of Test Cases
+#
+&tr.tc000 test_replace_fn=
+  @log smoke=Beginning replace() test cases.
+-
+#
+# Test Case #1 - Help file examples.
+#
+&tr.tc001 test_replace_fn=
+  @if strmatch(
+        setr(0,sha1(
+            [replace(This is a test, 4, quiz)]
+            [insert(Yet@Another@Mundane@List, 3, Funky, @)]
+          )
+        ),
+        928F739D325B8C8882EE7C4E32E6D5764AA08626
+      )=
+  {
+    @log smoke=TC001: Help file examples. Succeeded.
+  },
+  {
+    @log smoke=TC001: Help file examples. Failed (%q0).
+  }
+-
+#
+# Test Case #2 - Empty list. ASCII. Positive positions.
+#
+&tr.tc002 test_replace_fn=
+  @if strmatch(
+        setr(0,sha1(
+            [iter(0 1 2,## [replace(,##,Pear,|)])]
+          )
+        ),
+        6E58F1F3A34A9082AD078C3706E3067C0B22FE6E
+      )=
+  {
+    @log smoke=TC002: Empty list, ASCII, positive positions. Succeeded.
+  },
+  {
+    @log smoke=TC002: Empty list, ASCII, positive positions. Failed (%q0).
+  }
+-
+#
+# Test Case #3 - Non-empty lists. ASCII. Positive positions.
+#
+&tr.tc003 test_replace_fn=
+  @if strmatch(
+        setr(0,sha1(
+            [iter(0 1 2 3,## [replace(|,##,Pear,|)])]
+            [iter(0 1 2 3 4,## [replace(||,##,Pear,|)])]
+            [iter(0 1 2 3 4 5,## [replace(|||,##,Pear,|)])]
+          )
+        ),
+        40A8E0B4CA8FF2E2C9956AE9C09F9C68C8A16673
+      )=
+  {
+    @log smoke=TC003: Non-empty lists, ASCII, positive positions. Succeeded.
+  },
+  {
+    @log smoke=TC003: Non-empty lists, ASCII, positive positions. Failed (%q0).
+  }
+-
+#
+# Test Case #4 - Empty list. ASCII. Negative positions.
+#
+&tr.tc004 test_replace_fn=
+  @if strmatch(
+        setr(0,sha1(
+            [iter(-2 -1,## [replace(,##,Pear,|)])]
+          )
+        ),
+        5F364FF7EEEC93E30C5709B5184501A17046BDEA
+      )=
+  {
+    @log smoke=TC004: Empty list, ASCII, negative positions. Succeeded.
+  },
+  {
+    @log smoke=TC004: Empty list, ASCII, negative positions. Failed (%q0).
+  }
+-
+#
+# Test Case #5 - Non-empty lists. ASCII. Negative positions.
+#
+&tr.tc005 test_replace_fn=
+  @if strmatch(
+        setr(0,sha1(
+            [iter(-3 -2 -1,## [replace(|,##,Pear,|)])]
+            [iter(-4 -3 -2 -1,## [replace(||,##,Pear,|)])]
+            [iter(-5 -4 -3 -2 -1,## [replace(|||,##,Pear,|)])]
+          )
+        ),
+        29B941B8D4EE1193E602E3DDB0ED55DA5F86EFC9
+      )=
+  {
+    @log smoke=TC005: Non-empty lists, ASCII, negative positions. Succeeded.;
+    @trig me/tr.done
+  },
+  {
+    @log smoke=TC005: Non-empty lists, ASCII, negative positions. Failed (%q0).;
+    @trig me/tr.done
+  }
+-
+&tr.done test_replace_fn=
+  @log smoke=End replace() test cases.;
+  @notify smoke
+-
+drop test_replace_fn
+-
+#
+# End of Test Cases
+#
diff --git a/testcases/smoke.flat b/testcases/smoke.flat
index 78b744dbf..936f3e23d 100644
--- a/testcases/smoke.flat
+++ b/testcases/smoke.flat
@@ -1,5 +1,5 @@
 +X996100
-+S35
++S36
 +N273
 -R1
 +A256
@@ -40,7 +40,7 @@
 "Limbo"
 -1
 -1
-34
+35
 -1
 -1
 -1
@@ -88,7 +88,7 @@
 >84
 "#1;127.0.0.1;Fri Jan 01 00:00:00 2010;;;;;;;0;0;;;;;;;"
 >213
-"-1 34 -1 -1 34"
+"-1 35 -1 -1 35"
 >222
 "Shutdown"
 >224
@@ -572,15 +572,15 @@
 >256
 "@log smoke=Beginning insert() test cases."
 >257
-"@if strmatch(setr(0,sha1(insert(This is a test, 4, new)[insert(Yet@Another@List, 3, Funk, @)])),80194573F0E288397A859CD3A27CCF1FD922C8DB)={@log smoke=TC001: Help file examples. Succeeded.},{@log smoke=TC001: Help file examples. Failed (%q0).}"
+"@if strmatch(setr(0,sha1([insert(This is a test, 4, new)][insert(Yet@Another@List, 3, Funky, @)])),406626B7163831461CDED124D892909E9E351FCB)={@log smoke=TC001: Help file examples. Succeeded.},{@log smoke=TC001: Help file examples. Failed (%q0).}"
 >258
-"@if strmatch(setr(0,sha1(iter(0 1 2,## [insert(,##,Pear,|)]))),6A543151C6BDF80889FEAF3A53079DE952657E2A)={@log smoke=TC002: Empty list, ASCII, positive positions. Succeeded.},{@log smoke=TC002: Empty list, ASCII, positive positions. Failed (%q0).}"
+"@if strmatch(setr(0,sha1([iter(0 1 2,## [insert(,##,Pear,|)])])),6A543151C6BDF80889FEAF3A53079DE952657E2A)={@log smoke=TC002: Empty list, ASCII, positive positions. Succeeded.},{@log smoke=TC002: Empty list, ASCII, positive positions. Failed (%q0).}"
 >260
-"@if strmatch(setr(0,sha1(iter(0 1 2 3,## [insert(|,##,Pear,|)])iter(0 1 2 3 4,## [insert(||,##,Pear,|)])iter(0 1 2 3 4 5,## [insert(|||,##,Pear,|)]))),86316ADB7ADA940BCB55F7EE8BF4DE5E0852D34C)={@log smoke=TC003: Non-empty lists, ASCII, positive positions. Succeeded.},{@log smoke=TC003: Non-empty lists, ASCII, positive positions. Failed (%q0).}"
+"@if strmatch(setr(0,sha1([iter(0 1 2 3,## [insert(|,##,Pear,|)])][iter(0 1 2 3 4,## [insert(||,##,Pear,|)])][iter(0 1 2 3 4 5,## [insert(|||,##,Pear,|)])])),7CEB5283E8F723EF34A3468AE1CAD76D36517DCF)={@log smoke=TC003: Non-empty lists, ASCII, positive positions. Succeeded.},{@log smoke=TC003: Non-empty lists, ASCII, positive positions. Failed (%q0).}"
 >261
-"@if strmatch(setr(0,sha1(iter(-2 -1,## [insert(,##,Pear,|)]))),FF317BAF06BA80EED00C1E604E5A94C16EADAA8F)={@log smoke=TC004: Empty list, ASCII, negative positions. Succeeded.},{@log smoke=TC004: Empty list, ASCII, negative positions. Failed (%q0).}"
+"@if strmatch(setr(0,sha1([iter(-2 -1,## [insert(,##,Pear,|)])])),FF317BAF06BA80EED00C1E604E5A94C16EADAA8F)={@log smoke=TC004: Empty list, ASCII, negative positions. Succeeded.},{@log smoke=TC004: Empty list, ASCII, negative positions. Failed (%q0).}"
 >262
-"@if strmatch(setr(0,sha1(iter(-3 -2 -1,## [insert(|,##,Pear,|)])iter(-4 -3 -2 -1,## [insert(||,##,Pear,|)])iter(-5 -4 -3 -2 -1,## [insert(|||,##,Pear,|)]))),AA1255843386F29403032C2A238745291C562B90)={@log smoke=TC005: Non-empty lists, ASCII, negative positions. Succeeded.;@trig me/tr.done},{@log smoke=TC005: Non-empty lists, ASCII, negative positions. Failed (%q0).;@trig me/tr.done}"
+"@if strmatch(setr(0,sha1([iter(-3 -2 -1,## [insert(|,##,Pear,|)])][iter(-4 -3 -2 -1,## [insert(||,##,Pear,|)])][iter(-5 -4 -3 -2 -1,## [insert(|||,##,Pear,|)])])),377189E5484C2F769375C40A0540080FF649CE2F)={@log smoke=TC005: Non-empty lists, ASCII, negative positions. Succeeded.;@trig me/tr.done},{@log smoke=TC005: Non-empty lists, ASCII, negative positions. Failed (%q0).;@trig me/tr.done}"
 >259
 "@log smoke=End insert() test cases.;@notify smoke"
 <
@@ -856,7 +856,7 @@
 "@log smoke=End pickrand() test cases.;@notify smoke"
 <
 !23
-"test_rest_fn"
+"test_replace_fn"
 0
 -1
 -1
@@ -876,6 +876,41 @@
 >219
 "Fri Jan 01 00:00:00 2010"
 >256
+"@log smoke=Beginning replace() test cases."
+>257
+"@if strmatch(setr(0,sha1([replace(This is a test, 4, quiz)][insert(Yet@Another@Mundane@List, 3, Funky, @)])),928F739D325B8C8882EE7C4E32E6D5764AA08626)={@log smoke=TC001: Help file examples. Succeeded.},{@log smoke=TC001: Help file examples. Failed (%q0).}"
+>258
+"@if strmatch(setr(0,sha1([iter(0 1 2,## [replace(,##,Pear,|)])])),6E58F1F3A34A9082AD078C3706E3067C0B22FE6E)={@log smoke=TC002: Empty list, ASCII, positive positions. Succeeded.},{@log smoke=TC002: Empty list, ASCII, positive positions. Failed (%q0).}"
+>260
+"@if strmatch(setr(0,sha1([iter(0 1 2 3,## [replace(|,##,Pear,|)])][iter(0 1 2 3 4,## [replace(||,##,Pear,|)])][iter(0 1 2 3 4 5,## [replace(|||,##,Pear,|)])])),40A8E0B4CA8FF2E2C9956AE9C09F9C68C8A16673)={@log smoke=TC003: Non-empty lists, ASCII, positive positions. Succeeded.},{@log smoke=TC003: Non-empty lists, ASCII, positive positions. Failed (%q0).}"
+>261
+"@if strmatch(setr(0,sha1([iter(-2 -1,## [replace(,##,Pear,|)])])),5F364FF7EEEC93E30C5709B5184501A17046BDEA)={@log smoke=TC004: Empty list, ASCII, negative positions. Succeeded.},{@log smoke=TC004: Empty list, ASCII, negative positions. Failed (%q0).}"
+>262
+"@if strmatch(setr(0,sha1([iter(-3 -2 -1,## [replace(|,##,Pear,|)])][iter(-4 -3 -2 -1,## [replace(||,##,Pear,|)])][iter(-5 -4 -3 -2 -1,## [replace(|||,##,Pear,|)])])),29B941B8D4EE1193E602E3DDB0ED55DA5F86EFC9)={@log smoke=TC005: Non-empty lists, ASCII, negative positions. Succeeded.;@trig me/tr.done},{@log smoke=TC005: Non-empty lists, ASCII, negative positions. Failed (%q0).;@trig me/tr.done}"
+>259
+"@log smoke=End replace() test cases.;@notify smoke"
+<
+!24
+"test_rest_fn"
+0
+-1
+-1
+-1
+0
+23
+1
+-1
+1
+33556481
+0
+0
+0
+0
+>218
+"Fri Jan 01 00:00:00 2010"
+>219
+"Fri Jan 01 00:00:00 2010"
+>256
 "@log smoke=Beginning rest() test cases."
 >257
 "@if strmatch(setr(0,sha1([rest(This is a test)][rest(Would you like coffee, or perhaps tea)][rest(List!with!different!delimiters,!)])),948C7B2E7A1CB66F0BF5572D267B0D181B70764A)={@log smoke=TC001: rest examples. Succeeded.},{@log smoke=TC001: rest examples. Failed (%q0).}"
@@ -896,14 +931,14 @@
 >259
 "@log smoke=End rest() test cases.;@notify smoke"
 <
-!24
+!25
 "test_rjust_fn"
 0
 -1
 -1
 -1
 0
-23
+24
 1
 -1
 1
@@ -931,14 +966,14 @@
 >259
 "@log smoke=End rjust() test cases.;@notify smoke"
 <
-!25
+!26
 "test_rpad_fn"
 0
 -1
 -1
 -1
 0
-24
+25
 1
 -1
 1
@@ -966,14 +1001,14 @@
 >259
 "@log smoke=End rpad() test cases.;@notify smoke"
 <
-!26
+!27
 "test_secure_fn"
 0
 -1
 -1
 -1
 0
-25
+26
 1
 -1
 1
@@ -999,14 +1034,14 @@
 >259
 "@log smoke=End secure() test cases.;@notify smoke"
 <
-!27
+!28
 "test_sha1_fn"
 0
 -1
 -1
 -1
 0
-26
+27
 1
 -1
 1
@@ -1030,14 +1065,14 @@
 >259
 "@log smoke=End sha1() test cases.;@notify smoke"
 <
-!28
+!29
 "test_shl_fn"
 0
 -1
 -1
 -1
 0
-27
+28
 1
 -1
 1
@@ -1061,14 +1096,14 @@
 >259
 "@log smoke=End shl() test cases.;@notify smoke"
 <
-!29
+!30
 "test_shuffle_fn"
 0
 -1
 -1
 -1
 0
-28
+29
 1
 -1
 1
@@ -1104,14 +1139,14 @@
 >259
 "@log smoke=End shuffle() test cases.;@notify smoke"
 <
-!30
+!31
 "test_shutdown"
 0
 -1
 -1
 -1
 0
-29
+30
 1
 -1
 1
@@ -1127,14 +1162,14 @@
 >256
 "@log smoke=Ending SmokeMUX;@notify smoke;@shutdown"
 <
-!31
+!32
 "test_sin_fn"
 0
 -1
 -1
 -1
 0
-30
+31
 1
 -1
 1
@@ -1154,14 +1189,14 @@
 >259
 "@log smoke=End sin() test cases.;@notify smoke"
 <
-!32
+!33
 "smoke"
 0
 -1
 -1
 -1
 0
-31
+32
 1
 -1
 1
@@ -1175,20 +1210,20 @@
 >219
 "Fri Jan 01 00:00:00 2010"
 >271
-"accent_fn atan2_fn center_fn cmd_say columns_fn convtime_fn cpad_fn digest_fn edit_fn elements_fn escape_fn extract_fn first_fn insert_fn last_fn ldelete_fn ljust_fn lpad_fn merge_fn mid_fn pickrand_fn rest_fn rjust_fn rpad_fn secure_fn sha1_fn shuffle_fn shl_fn sin_fn sqrt_fn wrap_fn shutdown"
+"accent_fn atan2_fn center_fn cmd_say columns_fn convtime_fn cpad_fn digest_fn edit_fn elements_fn escape_fn extract_fn first_fn insert_fn last_fn ldelete_fn ljust_fn lpad_fn merge_fn mid_fn pickrand_fn replace_fn rest_fn rjust_fn rpad_fn secure_fn sha1_fn shuffle_fn shl_fn sin_fn sqrt_fn wrap_fn shutdown"
 >19
 "@log smoke=Starting SmokeMUX;@drain me;@dolist v(suite.list)={@trig me/suite.tr=##};@notify me"
 >272
 "@wait me={@dolist lattr(test_%0/tr.tc*)=@trig test_%0/##}"
 <
-!33
+!34
 "test_sqrt_fn"
 0
 -1
 -1
 -1
 0
-32
+33
 1
 -1
 1
@@ -1208,14 +1243,14 @@
 >259
 "@log smoke=End sqrt() test cases.;@notify smoke"
 <
-!34
+!35
 "test_wrap_fn"
 0
 -1
 -1
 -1
 0
-33
+34
 1
 -1
 1
diff --git a/testcases/smoke.mux b/testcases/smoke.mux
index e860aa4df..8768a1449 100644
--- a/testcases/smoke.mux
+++ b/testcases/smoke.mux
@@ -11,7 +11,7 @@
   center_fn cmd_say columns_fn convtime_fn cpad_fn digest_fn edit_fn 
   elements_fn escape_fn extract_fn 
   first_fn insert_fn last_fn ldelete_fn ljust_fn lpad_fn merge_fn mid_fn 
-  pickrand_fn 
+  pickrand_fn replace_fn 
   rest_fn rjust_fn rpad_fn secure_fn sha1_fn shuffle_fn shl_fn sin_fn sqrt_fn 
   wrap_fn shutdown
 -