diff --git a/examples/environment.js b/examples/environment.js
new file mode 100644
index 0000000..d79748e
--- /dev/null
+++ b/examples/environment.js
@@ -0,0 +1,19 @@
+import { compareTypes } from "../lib/compare/type.js";
+import { ModuleStd } from "../lib/stdlib.js";
+import { emptyDict, get, set } from "../lib/structures/dict.js";
+import { emptySet, add } from "../lib/structures/set.js";
+import { makeCompareFn } from "../lib/compare/dynamic.js"
+
+// console.log(ModuleStd);
+
+const typeDict = ModuleStd.reduce((typeDict, {i, t}) => {
+  try {
+    const instances = get(typeDict)(t) || emptySet(makeCompareFn(t));
+    return set(typeDict)(t)(add(instances)(i));  
+  } catch (e) {
+    console.log('warning:',e.message);
+    return typeDict;
+  }
+}, emptyDict(compareTypes));
+
+console.log(typeDict);
\ No newline at end of file