diff --git a/demos/examples/order-allocation/before.bosatsu b/demos/examples/order-allocation/after.bosatsu
index 52b0eb68..80009b49 100644
--- a/demos/examples/order-allocation/before.bosatsu
+++ b/demos/examples/order-allocation/after.bosatsu
@@ -65,12 +65,7 @@ def is_complete(allocation: Allocation) -> Bool:
   eq_Int(backordered, 0)

 def cart_preview(sku: String, stock: Stock, requested: Int) -> CartPreview:
-  allocation = Allocation(
-    nonnegative(requested),
-    min_int(nonnegative(requested), sellable_units(stock)),
-    nonnegative(requested).sub(min_int(nonnegative(requested), sellable_units(stock))),
-    sellable_units(stock).sub(min_int(nonnegative(requested), sellable_units(stock))),
-  )
+  allocation = allocation_plan(stock, requested)
   CartPreview(sku, allocation, is_complete(allocation))

 def checkout_order(order_id: String, stock: Stock, requested: Int) -> CheckoutDecision:
@@ -78,12 +73,7 @@ def checkout_order(order_id: String, stock: Stock, requested: Int) -> CheckoutDe
   CheckoutDecision(order_id, allocation, is_complete(allocation))

 def support_replacement(case_id: String, stock: Stock, requested: Int) -> SupportReplacement:
-  allocation = Allocation(
-    nonnegative(requested),
-    min_int(nonnegative(requested), sellable_units(stock)),
-    nonnegative(requested).sub(min_int(nonnegative(requested), sellable_units(stock))),
-    sellable_units(stock).sub(min_int(nonnegative(requested), sellable_units(stock))),
-  )
+  allocation = allocation_plan(stock, requested)
   status = if is_complete(allocation): Ready
   else: PartiallyBackordered
   SupportReplacement(case_id, allocation, status)