chore: reproduce bug for duplicate lagrange_first commitment

barretenberg/cpp/src/barretenberg/commitment_schemes/zeromorph/zeromorph.hpp

@@ -6,6 +6,7 @@
 #include "barretenberg/common/ref_vector.hpp"
 #include "barretenberg/common/zip_view.hpp"
 #include "barretenberg/polynomials/polynomial.hpp"
+#include "barretenberg/stdlib/primitives/biggroup/biggroup.hpp"
 #include "barretenberg/transcript/transcript.hpp"
 
 namespace bb {
@@ -489,7 +490,12 @@ template <typename PCS> class ZeroMorphVerifier_ {
 
         // Compute batch mul to get the result
         if constexpr (Curve::is_stdlib_type) {
-            return Commitment::batch_mul(commitments, scalars);
+            // If Ultra and using biggroup, handle edge cases in batch_mul
+            if constexpr (IsUltraBuilder<typename Curve::Builder> && stdlib::IsBigGroup<Commitment>) {
+                return Commitment::batch_mul(commitments, scalars, /*max_num_bits=*/0, /*with_edgecases=*/true);
+            } else {
+                return Commitment::batch_mul(commitments, scalars);
+            }
         } else {
             return batch_mul_native(commitments, scalars);
         }
@@ -604,7 +610,12 @@ template <typename PCS> class ZeroMorphVerifier_ {
         }
 
         if constexpr (Curve::is_stdlib_type) {
-            return Commitment::batch_mul(commitments, scalars);
+            // If Ultra and using biggroup, handle edge cases in batch_mul
+            if constexpr (IsUltraBuilder<typename Curve::Builder> && stdlib::IsBigGroup<Commitment>) {
+                return Commitment::batch_mul(commitments, scalars, /*max_num_bits=*/0, /*with_edgecases=*/true);
+            } else {
+                return Commitment::batch_mul(commitments, scalars);
+            }
         } else {
             return batch_mul_native(commitments, scalars);
         }
@@ -706,7 +717,12 @@ template <typename PCS> class ZeroMorphVerifier_ {
             auto builder = z_challenge.get_context();
             std::vector<FF> scalars = { FF(builder, 1), z_challenge };
             std::vector<Commitment> points = { C_zeta_x, C_Z_x };
-            C_zeta_Z = Commitment::batch_mul(points, scalars);
+            // If Ultra and using biggroup, handle edge cases in batch_mul
+            if constexpr (IsUltraBuilder<typename Curve::Builder> && stdlib::IsBigGroup<Commitment>) {
+                C_zeta_Z = Commitment::batch_mul(points, scalars, /*max_num_bits=*/0, /*with_edgecases=*/true);
+            } else {
+                C_zeta_Z = Commitment::batch_mul(points, scalars);
+            }
         } else {
             C_zeta_Z = C_zeta_x + C_Z_x * z_challenge;
         }

barretenberg/cpp/src/barretenberg/stdlib/honk_recursion/verifier/ultra_recursive_verifier.cpp

@@ -84,6 +84,8 @@ std::array<typename Flavor::GroupElement, 2> UltraRecursiveVerifier_<Flavor>::ve
         commitments.calldata = transcript->template receive_from_prover<Commitment>(commitment_labels.calldata);
         commitments.calldata_read_counts =
             transcript->template receive_from_prover<Commitment>(commitment_labels.calldata_read_counts);
+        commitments.calldata_read_tags =
+            transcript->template receive_from_prover<Commitment>(commitment_labels.calldata_read_tags);
         commitments.return_data = transcript->template receive_from_prover<Commitment>(commitment_labels.return_data);
         commitments.return_data_read_counts =
             transcript->template receive_from_prover<Commitment>(commitment_labels.return_data_read_counts);

barretenberg/cpp/src/barretenberg/stdlib/primitives/biggroup/biggroup.hpp

@@ -22,6 +22,7 @@ namespace bb::stdlib {
 template <class Builder, class Fq, class Fr, class NativeGroup> class element {
   public:
     using bool_ct = stdlib::bool_t<Builder>;
+    using biggroup_tag = element; // Facilitates a constexpr check IsBigGroup
 
     struct secp256k1_wnaf {
         std::vector<field_t<Builder>> wnaf;
@@ -937,6 +938,16 @@ template <class Builder, class Fq, class Fr, class NativeGroup> class element {
         typename std::conditional<HasPlookup<Builder>, batch_lookup_table_plookup<>, batch_lookup_table_base>::type;
 };
 
+// template <typename T>
+// concept IsBigGroup = requires {
+//     typename std::enable_if<
+//         std::is_same_v<T, element<typename T::Builder, typename T::Fq, typename T::Fr, typename
+//         T::NativeGroup>>>::type;
+// };
+
+template <typename T>
+concept IsBigGroup = std::is_same_v<typename T::biggroup_tag, T>;
+
 template <typename C, typename Fq, typename Fr, typename G>
 inline std::ostream& operator<<(std::ostream& os, element<C, Fq, Fr, G> const& v)
 {

barretenberg/cpp/src/barretenberg/stdlib_circuit_builders/mega_flavor.hpp

@@ -40,12 +40,12 @@ class MegaFlavor {
     // The number of multivariate polynomials on which a sumcheck prover sumcheck operates (including shifts). We often
     // need containers of this size to hold related data, so we choose a name more agnostic than `NUM_POLYNOMIALS`.
     // Note: this number does not include the individual sorted list polynomials.
-    static constexpr size_t NUM_ALL_ENTITIES = 58;
+    static constexpr size_t NUM_ALL_ENTITIES = 59;
     // The number of polynomials precomputed to describe a circuit and to aid a prover in constructing a satisfying
     // assignment of witnesses. We again choose a neutral name.
     static constexpr size_t NUM_PRECOMPUTED_ENTITIES = 30;
     // The total number of witness entities not including shifts.
-    static constexpr size_t NUM_WITNESS_ENTITIES = 17;
+    static constexpr size_t NUM_WITNESS_ENTITIES = 18;
     // Total number of folded polynomials, which is just all polynomials except the shifts
     static constexpr size_t NUM_FOLDED_ENTITIES = NUM_PRECOMPUTED_ENTITIES + NUM_WITNESS_ENTITIES;
 
@@ -188,6 +188,7 @@ class MegaFlavor {
                               ecc_op_wire_4,           // column 10
                               calldata,                // column 11
                               calldata_read_counts,    // column 12
+                              calldata_read_tags,      // column 12
                               calldata_inverses,       // column 13
                               return_data,             // column 14
                               return_data_read_counts, // column 15
@@ -664,6 +665,7 @@ class MegaFlavor {
             ecc_op_wire_4 = "ECC_OP_WIRE_4";
             calldata = "CALLDATA";
             calldata_read_counts = "CALLDATA_READ_COUNTS";
+            calldata_read_tags = "CALLDATA_READ_TAGS";
             calldata_inverses = "CALLDATA_INVERSES";
             return_data = "RETURN_DATA";
             return_data_read_counts = "RETURN_DATA_READ_COUNTS";
@@ -756,6 +758,7 @@ class MegaFlavor {
                 this->ecc_op_wire_4 = commitments.ecc_op_wire_4;
                 this->calldata = commitments.calldata;
                 this->calldata_read_counts = commitments.calldata_read_counts;
+                this->calldata_read_tags = commitments.calldata_read_tags;
                 this->calldata_inverses = commitments.calldata_inverses;
                 this->return_data = commitments.return_data;
                 this->return_data_read_counts = commitments.return_data_read_counts;
@@ -786,6 +789,7 @@ class MegaFlavor {
         Commitment ecc_op_wire_4_comm;
         Commitment calldata_comm;
         Commitment calldata_read_counts_comm;
+        Commitment calldata_read_tags_comm;
         Commitment calldata_inverses_comm;
         Commitment return_data_comm;
         Commitment return_data_read_counts_comm;
@@ -842,6 +846,7 @@ class MegaFlavor {
             ecc_op_wire_4_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
             calldata_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
             calldata_read_counts_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
+            calldata_read_tags_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
             calldata_inverses_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
             return_data_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
             return_data_read_counts_comm = deserialize_from_buffer<Commitment>(proof_data, num_frs_read);
@@ -883,6 +888,7 @@ class MegaFlavor {
             serialize_to_buffer(ecc_op_wire_4_comm, proof_data);
             serialize_to_buffer(calldata_comm, proof_data);
             serialize_to_buffer(calldata_read_counts_comm, proof_data);
+            serialize_to_buffer(calldata_read_tags_comm, proof_data);
             serialize_to_buffer(calldata_inverses_comm, proof_data);
             serialize_to_buffer(return_data_comm, proof_data);
             serialize_to_buffer(return_data_read_counts_comm, proof_data);

barretenberg/cpp/src/barretenberg/sumcheck/instance/prover_instance.cpp

@@ -43,6 +43,7 @@ void ProverInstance_<Flavor>::construct_databus_polynomials(Circuit& circuit)
 {
     auto& public_calldata = proving_key.polynomials.calldata;
     auto& calldata_read_counts = proving_key.polynomials.calldata_read_counts;
+    auto& calldata_read_tags = proving_key.polynomials.calldata_read_tags;
     auto& public_return_data = proving_key.polynomials.return_data;
     auto& return_data_read_counts = proving_key.polynomials.return_data_read_counts;
 
@@ -59,6 +60,12 @@ void ProverInstance_<Flavor>::construct_databus_polynomials(Circuit& circuit)
         return_data_read_counts[idx] = return_data.get_read_count(idx);
     }
 
+    // DEBUG: The issue seems to be related to have two identical commitments. If we swet calldata_read_tags[0] = 1,
+    // then its commitment is identical to [L_1]. If we set calldata_read_tags[0] = 2, there doesn't seem to be any
+    // problem.
+    calldata_read_tags[0] = 1; // This causes failure in Mega recursion with Ultra arith
+    // calldata_read_tags[0] = 2; // This causes the tests to pass
+
     auto& databus_id = proving_key.polynomials.databus_id;
     // Compute a simple identity polynomial for use in the databus lookup argument
     for (size_t i = 0; i < databus_id.size(); ++i) {

barretenberg/cpp/src/barretenberg/ultra_honk/oink_prover.cpp

@@ -91,9 +91,12 @@ template <IsUltraFlavor Flavor> void OinkProver<Flavor>::execute_wire_commitment
         // Commit to DataBus columns and corresponding read counts
         witness_commitments.calldata = commitment_key->commit(proving_key.polynomials.calldata);
         witness_commitments.calldata_read_counts = commitment_key->commit(proving_key.polynomials.calldata_read_counts);
+        witness_commitments.calldata_read_tags = commitment_key->commit(proving_key.polynomials.calldata_read_tags);
         transcript->send_to_verifier(domain_separator + commitment_labels.calldata, witness_commitments.calldata);
         transcript->send_to_verifier(domain_separator + commitment_labels.calldata_read_counts,
                                      witness_commitments.calldata_read_counts);
+        transcript->send_to_verifier(domain_separator + commitment_labels.calldata_read_tags,
+                                     witness_commitments.calldata_read_tags);
         witness_commitments.return_data = commitment_key->commit(proving_key.polynomials.return_data);
         witness_commitments.return_data_read_counts =
             commitment_key->commit(proving_key.polynomials.return_data_read_counts);

barretenberg/cpp/src/barretenberg/ultra_honk/oink_verifier.cpp

@@ -74,6 +74,8 @@ template <IsUltraFlavor Flavor> void OinkVerifier<Flavor>::execute_wire_commitme
             transcript->template receive_from_prover<Commitment>(domain_separator + comm_labels.calldata);
         witness_comms.calldata_read_counts =
             transcript->template receive_from_prover<Commitment>(domain_separator + comm_labels.calldata_read_counts);
+        witness_comms.calldata_read_tags =
+            transcript->template receive_from_prover<Commitment>(domain_separator + comm_labels.calldata_read_tags);
         witness_comms.return_data =
             transcript->template receive_from_prover<Commitment>(domain_separator + comm_labels.return_data);
         witness_comms.return_data_read_counts = transcript->template receive_from_prover<Commitment>(