diff --git a/docs/notebooks/BigInts.ipynb b/docs/notebooks/BigInts.ipynb
index a5a44d2..7727681 100644
--- a/docs/notebooks/BigInts.ipynb
+++ b/docs/notebooks/BigInts.ipynb
@@ -21,7 +21,15 @@
    "execution_count": 1,
    "id": "08a49b81",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "2147483648"
+     ]
+    }
+   ],
    "source": [
     "1 31 << "
    ]
@@ -39,7 +47,13 @@
    "execution_count": 2,
    "id": "b34d58ef",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": []
+    }
+   ],
    "source": [
     "unit [base] swoncat inscribe"
    ]
@@ -65,7 +79,13 @@
    "execution_count": 3,
    "id": "35476eac",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": []
+    }
+   ],
    "source": [
     "[valid_digit [0 >] [base <] &&] inscribe"
    ]
@@ -75,7 +95,15 @@
    "execution_count": 4,
    "id": "02a48806",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "32 true 1232147483648 false"
+     ]
+    }
+   ],
    "source": [
     "32 valid_digit 1232147483648 valid_digit"
    ]
@@ -85,7 +113,13 @@
    "execution_count": 5,
    "id": "03a8fe65",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": []
+    }
+   ],
    "source": [
     "clear"
    ]
@@ -112,7 +146,15 @@
    "execution_count": 6,
    "id": "3fc98ccd",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1797196498 5748904729"
+     ]
+    }
+   ],
    "source": [
     "12345678901234567890 base divmod swap"
    ]
@@ -122,7 +164,15 @@
    "execution_count": 7,
    "id": "b838c4cb",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1797196498 1453937433 2"
+     ]
+    }
+   ],
    "source": [
     "base divmod swap"
    ]
@@ -132,7 +182,15 @@
    "execution_count": 8,
    "id": "42c9d92d",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1797196498 1453937433 2 0"
+     ]
+    }
+   ],
    "source": [
     "base divmod swap"
    ]
@@ -152,7 +210,15 @@
    "execution_count": 9,
    "id": "faaac9d6",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1312754386 1501085485 57659106 105448366 58"
+     ]
+    }
+   ],
    "source": [
     "clear 1234567890123456789012345678901234567890\n",
     "\n",
@@ -172,7 +238,15 @@
    "execution_count": 10,
    "id": "2a613f36",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "[58 105448366 57659106 1501085485 1312754386]"
+     ]
+    }
+   ],
    "source": [
     "clear [1234567890123456789012345678901234567890]\n",
     "\n",
@@ -5079,7 +5153,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 211,
+   "execution_count": 192,
    "id": "90abab0f",
    "metadata": {},
    "outputs": [
@@ -5103,7 +5177,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 212,
+   "execution_count": 193,
    "id": "391d87fe",
    "metadata": {},
    "outputs": [
@@ -5119,17 +5193,25 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 194,
    "id": "a7cce3f2",
    "metadata": {},
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "123"
+     ]
+    }
+   ],
    "source": [
     "123 "
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 213,
+   "execution_count": 195,
    "id": "edb25ebd",
    "metadata": {},
    "outputs": [
@@ -5147,7 +5229,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 214,
+   "execution_count": 196,
    "id": "06e2f309",
    "metadata": {},
    "outputs": [
@@ -5165,7 +5247,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 215,
+   "execution_count": 197,
    "id": "dd47bdae",
    "metadata": {},
    "outputs": [
@@ -5181,6 +5263,23 @@
     "[add-bigints [same-sign] [add-like-bigints] [neg-bigint sub-like-bigints] ifte] inscribe"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "id": "de5f0dd7",
+   "metadata": {},
+   "source": [
+    "## Multiplication\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "89d38381",
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
   {
    "cell_type": "markdown",
    "id": "f2b707c1",
diff --git a/implementations/bigints.joy b/implementations/bigints.joy
index bb95762..5fa153d 100644
--- a/implementations/bigints.joy
+++ b/implementations/bigints.joy
@@ -32,14 +32,7 @@ clear
 
 [add-digits initial-carry add-digits']
 [initial-carry false rollup]
-[add-digits' [P] [THEN] [R0] [R1] genrec]
-[P [bool] ii & not]
-[THEN [P'] [THEN'] [ELSE] ifte]
-[R0 uncons-two [add-with-carry] dipd]
-[R1 i cons]
-[P' [bool] ii |]
-[THEN' ditch-empty-list add-carry-to-digits]
-[ELSE pop swap [] [1 swons] branch]
+
 
 [same-sign [first] ii xor not]
 [extract-sign [uncons] dip rest]
@@ -54,6 +47,8 @@ clear
 [_btlc0.4 [uncons-two] [dipd] sandwich]
 [_btlc0 _btlc0.3 _btlc0.4]
 [_btlc1 [[ifte] ccons [P'] swons [P] swap] dip]
+[P [bool] ii & not]
+[P' [bool] ii |]
 
 [carry [] [1 swons] branch]