diff --git a/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res b/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
index a2fa37df..ecc07bfa 100644
--- a/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
+++ b/packages/squiggle-lang/__tests__/ReducerInterface/ReducerInterface_Distribution_test.res
@@ -80,6 +80,7 @@ describe("eval on distribution functions", () => {
     testEval("truncateLeft(normal(5,2), 3)", "Ok(Point Set Distribution)")
     testEval("truncateRight(normal(5,2), 3)", "Ok(Point Set Distribution)")
     testEval("truncate(normal(5,2), 3, 8)", "Ok(Point Set Distribution)")
+    testEval("isNormalized(truncate(normal(5,2), 3, 8))", "Ok(true)")
   })
 
   describe("exp", () => {
diff --git a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_StdLib.res b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_StdLib.res
index 43823007..b714790a 100644
--- a/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_StdLib.res
+++ b/packages/squiggle-lang/src/rescript/ReducerInterface/ReducerInterface_StdLib.res
@@ -2,4 +2,5 @@ module Module = Reducer_Category_Module
 
 let internalStdLib = Module.emptyModule->SquiggleLibrary_Math.makeBindings
 
+@genType
 let externalStdLib = internalStdLib->Module.toTypeScriptBindings
diff --git a/packages/squiggle-lang/src/rescript/SquiggleLibrary/SquiggleLibrary_Math.res b/packages/squiggle-lang/src/rescript/SquiggleLibrary/SquiggleLibrary_Math.res
index 13550eda..4dc59b56 100644
--- a/packages/squiggle-lang/src/rescript/SquiggleLibrary/SquiggleLibrary_Math.res
+++ b/packages/squiggle-lang/src/rescript/SquiggleLibrary/SquiggleLibrary_Math.res
@@ -1,8 +1,23 @@
 module Bindings = Reducer_Category_Module
 module Module = Reducer_Category_Module
 
-let m =
-  Module.emptyModule->Module.defineNumber("pi", Js.Math._PI)->Module.defineNumber("e", Js.Math._E)
+let availableNumbers: array<(string, float)> = [
+  ("pi", Js.Math._PI),
+  ("e", Js.Math._E),
+  ("ln2", Js.Math._LN2),
+  ("ln10", Js.Math._LN10),
+  ("log2e", Js.Math._LOG2E),
+  ("log10e", Js.Math._LOG10E),
+  ("sqrt2", Js.Math._SQRT2),
+  ("sqrt1_2", Js.Math._SQRT1_2),
+  ("phi", 1.618033988749895),
+  ("tau", 6.283185307179586),
+]
 
-let makeBindings = (previousBindings: Module.t): Module.t =>
-  previousBindings->Bindings.defineModule("Math", m)
+let mathBindings: Bindings.t =
+  availableNumbers
+  ->E.A2.fmap(((name, v)) => (name, ReducerInterface_InternalExpressionValue.IevNumber(v)))
+  ->Bindings.fromArray
+
+let makeBindings = (previousBindings: Bindings.t): Bindings.t =>
+  previousBindings->Bindings.defineModule("Math", mathBindings)