remove old cruft

environments.js

@@ -42,14 +42,7 @@ function lookup(name, env) {
   return value;
 }
 
-var prelude = makeEnv("prelude", [[new rep.Name("e"), new rep.FloatT(Math.E)],
-                                  [new rep.Name("pi"), new rep.FloatT(Math.PI)]]);
-
-var prelude_types = makeEnv("prelude_types",
-                            [[new rep.Name("e"), new rep.TypeOp("Float", [], false)],
-                            [new rep.Name("pi"), new rep.TypeOp("Float", [], false)]]);
-
-module.exports = { prelude : prelude,
-                   prelude_types : prelude_types,
-                   lookup : lookup,
-                   extend : extend };
+module.exports = {
+  lookup : lookup,
+  extend : extend
+};