From af9a2c055c9844a8004603c22794cdbeeed5a3c8 Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Wed, 30 Jun 2021 14:02:20 -0700
Subject: [PATCH] some fixes

---
 src/gadgets/insert.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/gadgets/insert.rs b/src/gadgets/insert.rs
index 8cb4614d..d1e0331d 100644
--- a/src/gadgets/insert.rs
+++ b/src/gadgets/insert.rs
@@ -35,7 +35,9 @@ impl<F: Extendable<D>, const D: usize> CircuitBuilder<F, D> {
             new_item = self.add(new_item, self.mul(insert_here, element));
             new_item = self.add(new_item, self.mul(already_inserted, v[i-1]));
             already_inserted = self.add(already_inserted, insert_here);
-            new_item = self.add(new_item, self.mul(self.sub(self.one(), already_inserted), v[i]));
+
+            let not_already_inserted = self.sub(self.one(), already_inserted);
+            new_item = self.mul_add(not_already_inserted, v[i], new_item);
 
             new_list.push(new_item);
         }