diff --git a/package.json b/package.json
index 02d35dc530..dd4d4d2594 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
     "flexboxgrid": "^6.3.1",
     "flexboxgrid-helpers": "^1.1.3",
     "hastscript": "^9.0.0",
-    "js-slang": "^1.0.50",
+    "js-slang": "^1.0.51",
     "js-yaml": "^4.1.0",
     "konva": "^9.2.0",
     "lodash": "^4.17.21",
diff --git a/src/features/cseMachine/__tests__/__snapshots__/CseMachine.tsx.snap b/src/features/cseMachine/__tests__/__snapshots__/CseMachine.tsx.snap
index 78ddeb8d1b..7555d226f2 100644
--- a/src/features/cseMachine/__tests__/__snapshots__/CseMachine.tsx.snap
+++ b/src/features/cseMachine/__tests__/__snapshots__/CseMachine.tsx.snap
@@ -2111,7 +2111,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "1",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -2347,7 +2347,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "57",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -2538,7 +2538,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "107",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -2727,7 +2727,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "154",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -2898,7 +2898,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "205",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -3015,7 +3015,7 @@ Object {
         "stream_to_list": [Function],
       },
       "id": "205",
-      "name": "programEnvironment",
+      "name": "prelude",
       "tail": Object {
         "head": Object {
           ":::pre-declared names::": Symbol(),
@@ -3126,7 +3126,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "256",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -3230,7 +3230,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "303",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         ":::pre-declared names::": Symbol(),
@@ -3331,7 +3331,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "350",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         "411": [Function],
@@ -3443,7 +3443,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "350",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         "411": [Function],
@@ -3554,7 +3554,7 @@ Object {
       "stream_to_list": [Function],
     },
     "id": "350",
-    "name": "programEnvironment",
+    "name": "prelude",
     "tail": Object {
       "head": Object {
         "411": [Function],
@@ -3641,7 +3641,7 @@ Object {
         "stream_to_list": [Function],
       },
       "id": "350",
-      "name": "programEnvironment",
+      "name": "prelude",
       "tail": Object {
         "head": Object {
           "411": [Function],
@@ -3779,7 +3779,7 @@ Object {
         "stream_to_list": [Function],
       },
       "id": "350",
-      "name": "programEnvironment",
+      "name": "prelude",
       "tail": Object {
         "head": Object {
           "411": [Function],
@@ -3873,7 +3873,7 @@ Object {
           "stream_to_list": [Function],
         },
         "id": "350",
-        "name": "programEnvironment",
+        "name": "prelude",
         "tail": Object {
           "head": Object {
             "411": [Function],
@@ -3968,7 +3968,7 @@ Object {
           "stream_to_list": [Function],
         },
         "id": "350",
-        "name": "programEnvironment",
+        "name": "prelude",
         "tail": Object {
           "head": Object {
             "411": [Function],
@@ -4063,7 +4063,7 @@ Object {
           "stream_to_list": [Function],
         },
         "id": "350",
-        "name": "programEnvironment",
+        "name": "prelude",
         "tail": Object {
           "head": Object {
             "411": [Function],
@@ -4158,7 +4158,7 @@ Object {
           "stream_to_list": [Function],
         },
         "id": "350",
-        "name": "programEnvironment",
+        "name": "prelude",
         "tail": Object {
           "head": Object {
             "411": [Function],
@@ -4303,7 +4303,7 @@ Object {
           "stream_to_list": [Function],
         },
         "id": "350",
-        "name": "programEnvironment",
+        "name": "prelude",
         "tail": Object {
           "head": Object {
             "411": [Function],
@@ -4404,7 +4404,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -4506,7 +4506,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -4608,7 +4608,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -4710,7 +4710,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -4912,7 +4912,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -5114,7 +5114,7 @@ Object {
             "stream_to_list": [Function],
           },
           "id": "350",
-          "name": "programEnvironment",
+          "name": "prelude",
           "tail": Object {
             "head": Object {
               "411": [Function],
@@ -5224,7 +5224,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
@@ -5335,7 +5335,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
@@ -5446,7 +5446,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
@@ -5557,7 +5557,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
@@ -5775,7 +5775,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
@@ -5993,7 +5993,7 @@ Object {
               "stream_to_list": [Function],
             },
             "id": "350",
-            "name": "programEnvironment",
+            "name": "prelude",
             "tail": Object {
               "head": Object {
                 "411": [Function],
diff --git a/yarn.lock b/yarn.lock
index 838676c677..86b137940c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8305,10 +8305,10 @@ js-sdsl@4.3.0, js-sdsl@^4.1.4:
   resolved "https://registry.yarnpkg.com/js-sdsl/-/js-sdsl-4.3.0.tgz#aeefe32a451f7af88425b11fdb5f58c90ae1d711"
   integrity sha512-mifzlm2+5nZ+lEcLJMoBK0/IH/bDg8XnJfd/Wq6IP+xoCjLZsTOnV2QpxlVbX9bMnkl5PdEjNtBJ9Cj1NjifhQ==
 
-js-slang@^1.0.50:
-  version "1.0.50"
-  resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-1.0.50.tgz#a18a7d02013b1e3555b5d5bea425ccee26d5b153"
-  integrity sha512-zgxhCUdAqh0TRCU5eizE35AgQYmxZyBhH8AnRap4eI1T5krGRlHwXzy9r05pTTKnK1LjR09sNVM6W7ai/i9q0w==
+js-slang@^1.0.51:
+  version "1.0.51"
+  resolved "https://registry.yarnpkg.com/js-slang/-/js-slang-1.0.51.tgz#254ec52f4db29a8f51276cf681cf2608698337cf"
+  integrity sha512-UmoWDfcgwxG86s+Q7y9BxU8PcPnyyTs6jgVK77luaGqMy+kDKwwNqajjIOmd3thVOouAj2U1llAjVT1oZtmCLw==
   dependencies:
     "@babel/parser" "^7.19.4"
     "@joeychenofficial/alt-ergo-modified" "^2.4.0"