From 66e4f7c3cf1261e8d44cd5f09f2f6c73499e4f0b Mon Sep 17 00:00:00 2001
From: Nicholas Ward <npward@berkeley.edu>
Date: Mon, 12 Jul 2021 12:14:14 -0700
Subject: [PATCH] added output constraint

---
 src/gates/insertion.rs | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/gates/insertion.rs b/src/gates/insertion.rs
index 81874a7e..5ddc9168 100644
--- a/src/gates/insertion.rs
+++ b/src/gates/insertion.rs
@@ -5,7 +5,7 @@ use std::marker::PhantomData;
 use crate::circuit_builder::CircuitBuilder;
 use crate::field::extension_field::algebra::ExtensionAlgebra;
 use crate::field::extension_field::target::ExtensionTarget;
-use crate::field::extension_field::Extendable;
+use crate::field::extension_field::{FieldExtension, Extendable};
 use crate::field::field::Field;
 use crate::gates::gate::{Gate, GateRef};
 use crate::generator::{SimpleGenerator, WitnessGenerator};
@@ -70,17 +70,25 @@ impl<F: Extendable<D>, const D: usize> Gate<F, D> for InsertionGate<F, D> {
 
     fn eval_unfiltered(&self, vars: EvaluationVars<F, D>) -> Vec<F::Extension> {
         let insertion_index = vars.local_wires[Self::wires_insertion_index()];
+        
         let mut list_items = Vec::new();
         for i in 0..self.vec_size {
             list_items.push(vars.get_local_ext_algebra(Self::wires_list_item(i)));
         }
+        let dummy_value : ExtensionAlgebra<F::Extension, D> = F::Extension::ZERO.into(); // will never be reached
+        list_items.push(dummy_value);
+
+        let mut output_list_items = Vec::new();
+        for i in 0..self.vec_size+1 {
+            output_list_items.push(vars.get_local_ext_algebra(self.wires_output_list_item(i)));
+        }
 
         let element_to_insert = vars.get_local_ext_algebra(Self::wires_element_to_insert());
 
         let mut constraints = Vec::new();
 
         let mut already_inserted : ExtensionAlgebra<F::Extension, D> = F::Extension::ZERO.into();
-        for r in 0..self.vec_size {
+        for r in 0..self.vec_size + 1 {
             let cur_index = F::Extension::from_canonical_usize(r);
             
             let equality_dummy = vars.get_local_ext_algebra(self.equality_dummy_for_round_r(r));
@@ -93,7 +101,8 @@ impl<F: Extendable<D>, const D: usize> Gate<F, D> for InsertionGate<F, D> {
             };
             
             // The two equality constraints:
-            let equality_dummy_constraint : ExtensionAlgebra<F::Extension, D> = difference.into() * equality_dummy - insert_here;
+            let difference_algebra : ExtensionAlgebra<F::Extension, D> = difference.into();
+            let equality_dummy_constraint : ExtensionAlgebra<F::Extension, D> = difference_algebra * equality_dummy - insert_here;
             constraints.extend(equality_dummy_constraint.to_basefield_array());
             let mul_to_zero_constraint : ExtensionAlgebra<F::Extension, D> = (F::Extension::ONE.into() - insert_here) * difference;
             constraints.extend(mul_to_zero_constraint.to_basefield_array());
@@ -105,6 +114,8 @@ impl<F: Extendable<D>, const D: usize> Gate<F, D> for InsertionGate<F, D> {
             already_inserted += insert_here;
 
             new_item += (F::Extension::ONE.into() - already_inserted) * list_items[r];
+
+            constraints.extend((new_item - output_list_items[r]).to_basefield_array());
         }
 
         constraints