qp-plonky2 1.4.1

Recursive SNARKs based on PLONK and FRI
Documentation
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#[cfg(not(feature = "std"))]
use alloc::{sync::Arc, vec, vec::Vec};
#[cfg(feature = "std")]
use std::sync::{Arc, Once};

use itertools::Itertools;
use log::Level;

use crate::field::types::Field;
use crate::gadgets::lookup::{OTHER_TABLE, SMALLER_TABLE, TIP5_TABLE};
use crate::gates::lookup_table::LookupTable;
use crate::gates::noop::NoopGate;
use crate::iop::witness::{PartialWitness, WitnessWrite};
use crate::plonk::circuit_builder::CircuitBuilder;
use crate::plonk::circuit_data::CircuitConfig;
use crate::plonk::config::{GenericConfig, PoseidonGoldilocksConfig};
use crate::plonk::prover::prove;
use crate::util::timing::TimingTree;

const D: usize = 2;
type C = PoseidonGoldilocksConfig;
type F = <C as GenericConfig<D>>::F;

const LUT_SIZE: usize = u16::MAX as usize + 1;

#[cfg(feature = "std")]
static LOGGER_INITIALIZED: Once = Once::new();

#[test]
fn test_no_lookup() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);
    builder.add_gate(NoopGate, vec![]);
    let pw = PartialWitness::new();

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove first", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    timing.print();
    data.verify(proof)?;

    Ok(())
}

#[should_panic]
#[test]
fn test_lookup_table_not_used() {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    builder.add_lookup_table_from_pairs(table);

    builder.build::<C>();
}

#[should_panic]
#[test]
fn test_lookup_without_table() {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let dummy = builder.add_virtual_target();
    builder.add_lookup_from_index(dummy, 0);

    builder.build::<C>();
}

// Tests two lookups in one lookup table.
#[test]
fn test_one_lookup() -> anyhow::Result<()> {
    init_logger();

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 1;
    let look_val_b = 2;

    let out_a = table[look_val_a].1;
    let out_b = table[look_val_b].1;
    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);

    let output_b = builder.add_lookup_from_index(initial_b, table_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let mut pw = PartialWitness::new();

    pw.set_target(initial_a, F::from_canonical_usize(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_usize(look_val_b))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove one lookup", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    timing.print();
    data.verify(proof.clone())?;

    assert!(
        proof.public_inputs[2] == F::from_canonical_u16(out_a),
        "First lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[0]
    );
    assert!(
        proof.public_inputs[3] == F::from_canonical_u16(out_b),
        "Second lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[1]
    );

    Ok(())
}

#[cfg(feature = "rand")]
#[test]
fn test_one_lookup_row_blinding() -> anyhow::Result<()> {
    init_logger();

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    let config = CircuitConfig::standard_recursion_zk_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 1;
    let look_val_b = 2;

    let out_a = table[look_val_a].1;
    let out_b = table[look_val_b].1;
    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);
    let output_b = builder.add_lookup_from_index(initial_b, table_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let mut pw = PartialWitness::new();
    pw.set_target(initial_a, F::from_canonical_usize(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_usize(look_val_b))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove one lookup with row blinding", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    timing.print();
    data.verify(proof.clone())?;

    assert!(proof.proof.opening_proof.batch_mask_proof.is_none());

    assert_eq!(proof.public_inputs[2], F::from_canonical_u16(out_a));
    assert_eq!(proof.public_inputs[3], F::from_canonical_u16(out_b));

    Ok(())
}

#[cfg(feature = "rand")]
#[test]
fn test_one_lookup_polyfri() -> anyhow::Result<()> {
    init_logger();

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    let config = CircuitConfig::standard_recursion_polyfri_zk_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);
    let output_b = builder.add_lookup_from_index(initial_b, table_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let mut pw = PartialWitness::new();
    pw.set_target(initial_a, F::from_canonical_usize(1))?;
    pw.set_target(initial_b, F::from_canonical_usize(2))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove one lookup with PolyFri", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    timing.print();
    data.verify(proof.clone())?;

    assert!(
        proof.proof.opening_proof.batch_mask_proof.is_some(),
        "PolyFri proofs must carry an explicit batch-mask proof"
    );

    Ok(())
}

/// Test that PolyFri proofs can be serialized, deserialized, and verified using the
/// standalone verifier crate (same path as on-chain verification).
#[cfg(feature = "rand")]
#[test]
fn test_polyfri_proof_serialization_roundtrip() -> anyhow::Result<()> {
    // Use prover crate's serializer for serialization
    // Use the standalone verifier crate types - this is the same code path as on-chain verification
    use plonky2_verifier::plonk::circuit_data::{CommonCircuitData, VerifierCircuitData};
    use plonky2_verifier::plonk::proof::ProofWithPublicInputs;
    use plonky2_verifier::util::serialization::DefaultGateSerializer as VerifierGateSerializer;

    use crate::util::serialization::DefaultGateSerializer as ProverGateSerializer;

    init_logger();

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    let config = CircuitConfig::standard_recursion_polyfri_zk_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);
    let output_b = builder.add_lookup_from_index(initial_b, table_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let mut pw = PartialWitness::new();
    pw.set_target(initial_a, F::from_canonical_usize(1))?;
    pw.set_target(initial_b, F::from_canonical_usize(2))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove polyfri serialization roundtrip", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    timing.print();

    // Verify directly first (using prover crate's verify)
    data.verify(proof.clone())?;

    // Serialize common data using prover's serializer
    let prover_gate_serializer = ProverGateSerializer;
    let common_bytes = data
        .common
        .to_bytes(&prover_gate_serializer)
        .expect("serialize common");

    // Serialize verifier data
    let verifier_bytes = data.verifier_only.to_bytes().expect("serialize verifier");

    // Serialize proof
    let proof_bytes = proof.to_bytes();

    // Deserialize using the VERIFIER CRATE types (not prover crate)
    // This is the same code path used by on-chain verification
    let verifier_gate_serializer = VerifierGateSerializer;
    let common_deserialized =
        CommonCircuitData::<F, D>::from_bytes(common_bytes, &verifier_gate_serializer)
            .expect("deserialize common");

    // Deserialize verifier data using verifier crate
    let verifier_deserialized = plonky2_verifier::plonk::circuit_data::VerifierOnlyCircuitData::<
        C,
        D,
    >::from_bytes(verifier_bytes)
    .expect("deserialize verifier");

    // Deserialize proof using verifier crate
    let proof_deserialized =
        ProofWithPublicInputs::<F, C, D>::from_bytes(proof_bytes, &common_deserialized)
            .expect("deserialize proof");

    // Verify with verifier crate's VerifierCircuitData - this exercises the verifier's vanishing_poly.rs
    let verifier_data = VerifierCircuitData {
        verifier_only: verifier_deserialized,
        common: common_deserialized,
    };
    verifier_data.verify(proof_deserialized)?;

    Ok(())
}

#[cfg(feature = "rand")]
#[test]
fn test_one_lookup_polyfri_batch_mask_cap_tamper_fails() -> anyhow::Result<()> {
    init_logger();

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());
    let config = CircuitConfig::standard_recursion_polyfri_zk_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);
    let output_b = builder.add_lookup_from_index(initial_b, table_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let mut pw = PartialWitness::new();
    pw.set_target(initial_a, F::from_canonical_usize(1))?;
    pw.set_target(initial_b, F::from_canonical_usize(2))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new(
        "prove one lookup with PolyFri batch-mask tamper",
        Level::Debug,
    );
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    data.verify(proof.clone())?;

    let mut corrupted_proof = proof;
    corrupted_proof
        .proof
        .opening_proof
        .batch_mask_proof
        .as_mut()
        .expect("PolyFri proofs must carry an explicit batch-mask proof")
        .cap
        .0[0]
        .elements[0] += F::ONE;

    assert!(data.verify(corrupted_proof).is_err());

    Ok(())
}

// Tests one lookup in two different lookup tables.
#[test]
fn test_two_luts() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 1;
    let look_val_b = 2;

    let tip5_table = TIP5_TABLE.to_vec();

    let first_out = tip5_table[look_val_a];
    let second_out = tip5_table[look_val_b];

    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());

    let other_table = OTHER_TABLE.to_vec();

    let table_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, table_index);

    let output_b = builder.add_lookup_from_index(initial_b, table_index);
    let sum = builder.add(output_a, output_b);

    let s = first_out + second_out;
    let final_out = other_table[s as usize];

    let table2: LookupTable = Arc::new((0..256).zip_eq(other_table).collect());
    let table2_index = builder.add_lookup_table_from_pairs(table2);

    let output_final = builder.add_lookup_from_index(sum, table2_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(sum);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);
    builder.register_public_input(output_final);

    let mut pw = PartialWitness::new();
    pw.set_target(initial_a, F::from_canonical_usize(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_usize(look_val_b))?;
    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove two_luts", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    data.verify(proof.clone())?;
    timing.print();

    assert!(
        proof.public_inputs[3] == F::from_canonical_u16(first_out),
        "First lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[0]
    );
    assert!(
        proof.public_inputs[4] == F::from_canonical_u16(second_out),
        "Second lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[1]
    );
    assert!(
        proof.public_inputs[2] == F::from_canonical_u16(s),
        "Sum between the first two LUT outputs is incorrect."
    );
    assert!(
        proof.public_inputs[5] == F::from_canonical_u16(final_out),
        "Output of the second LUT at index {} is incorrect.",
        s
    );

    Ok(())
}

#[test]
fn test_different_inputs() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let init_a = 1;
    let init_b = 2;

    let tab: Vec<u16> = SMALLER_TABLE.to_vec();
    let table: LookupTable = Arc::new((2..10).zip_eq(tab).collect());

    let other_table = OTHER_TABLE.to_vec();

    let table2: LookupTable = Arc::new((0..256).zip_eq(other_table).collect());
    let small_index = builder.add_lookup_table_from_pairs(table.clone());
    let output_a = builder.add_lookup_from_index(initial_a, small_index);

    let output_b = builder.add_lookup_from_index(initial_b, small_index);
    let sum = builder.add(output_a, output_b);

    let other_index = builder.add_lookup_table_from_pairs(table2.clone());
    let output_final = builder.add_lookup_from_index(sum, other_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(sum);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);
    builder.register_public_input(output_final);

    let mut pw = PartialWitness::new();

    let look_val_a = table[init_a].0;
    let look_val_b = table[init_b].0;
    pw.set_target(initial_a, F::from_canonical_u16(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_u16(look_val_b))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove different lookups", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    data.verify(proof.clone())?;
    timing.print();

    let out_a = table[init_a].1;
    let out_b = table[init_b].1;
    let s = out_a + out_b;
    let out_final = table2[s as usize].1;

    assert!(
        proof.public_inputs[3] == F::from_canonical_u16(out_a),
        "First lookup, at index {} in the smaller LUT gives an incorrect output.",
        proof.public_inputs[0]
    );
    assert!(
        proof.public_inputs[4] == F::from_canonical_u16(out_b),
        "Second lookup, at index {} in the smaller LUT gives an incorrect output.",
        proof.public_inputs[1]
    );
    assert!(
        proof.public_inputs[2] == F::from_canonical_u16(s),
        "Sum between the first two LUT outputs is incorrect."
    );
    assert!(
        proof.public_inputs[5] == F::from_canonical_u16(out_final),
        "Output of the second LUT at index {} is incorrect.",
        s
    );

    Ok(())
}

// This test looks up over 514 values for one LookupTableGate, which means that several LookupGates are created.
#[test]
fn test_many_lookups() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 1;
    let look_val_b = 2;

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());

    let out_a = table[look_val_a].1;
    let out_b = table[look_val_b].1;

    let tip5_index = builder.add_lookup_table_from_pairs(table);
    let output_a = builder.add_lookup_from_index(initial_a, tip5_index);

    let output_b = builder.add_lookup_from_index(initial_b, tip5_index);
    let sum = builder.add(output_a, output_b);

    for _ in 0..514 {
        builder.add_lookup_from_index(initial_a, tip5_index);
    }

    let other_table = OTHER_TABLE.to_vec();

    let table2: LookupTable = Arc::new((0..256).zip_eq(other_table).collect());

    let s = out_a + out_b;
    let out_final = table2[s as usize].1;

    let other_index = builder.add_lookup_table_from_pairs(table2);
    let output_final = builder.add_lookup_from_index(sum, other_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(sum);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);
    builder.register_public_input(output_final);

    let mut pw = PartialWitness::new();

    pw.set_target(initial_a, F::from_canonical_usize(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_usize(look_val_b))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove different lookups", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;

    data.verify(proof.clone())?;
    timing.print();

    assert!(
        proof.public_inputs[3] == F::from_canonical_u16(out_a),
        "First lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[0]
    );
    assert!(
        proof.public_inputs[4] == F::from_canonical_u16(out_b),
        "Second lookup, at index {} in the Tip5 table gives an incorrect output.",
        proof.public_inputs[1]
    );
    assert!(
        proof.public_inputs[2] == F::from_canonical_u16(s),
        "Sum between the first two LUT outputs is incorrect."
    );
    assert!(
        proof.public_inputs[5] == F::from_canonical_u16(out_final),
        "Output of the second LUT at index {} is incorrect.",
        s
    );

    Ok(())
}

// Tests whether, when adding the same LUT to the circuit, the circuit only adds one copy, with the same index.
#[test]
fn test_same_luts() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 1;
    let look_val_b = 2;

    let tip5_table = TIP5_TABLE.to_vec();
    let table: LookupTable = Arc::new((0..256).zip_eq(tip5_table).collect());

    let table_index = builder.add_lookup_table_from_pairs(table.clone());
    let output_a = builder.add_lookup_from_index(initial_a, table_index);

    let output_b = builder.add_lookup_from_index(initial_b, table_index);
    let sum = builder.add(output_a, output_b);

    let table2_index = builder.add_lookup_table_from_pairs(table);

    let output_final = builder.add_lookup_from_index(sum, table2_index);

    builder.register_public_input(initial_a);
    builder.register_public_input(initial_b);
    builder.register_public_input(sum);
    builder.register_public_input(output_a);
    builder.register_public_input(output_b);
    builder.register_public_input(output_final);

    let luts_length = builder.get_luts_length();

    assert!(
        luts_length == 1,
        "There are {} LUTs when there should be only one",
        luts_length
    );

    let mut pw = PartialWitness::new();

    pw.set_target(initial_a, F::from_canonical_usize(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_usize(look_val_b))?;

    let data = builder.build::<C>();
    let mut timing = TimingTree::new("prove two_luts", Level::Debug);
    let proof = prove(&data.prover_only, &data.common, pw, &mut timing)?;
    data.verify(proof)?;
    timing.print();

    Ok(())
}

#[test]
fn test_big_lut() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let inputs: [u16; LUT_SIZE] = core::array::from_fn(|i| i as u16);
    let lut_fn = |inp: u16| inp / 10;
    let lut_index = builder.add_lookup_table_from_fn(lut_fn, &inputs);

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 51;
    let look_val_b = 2;

    let output_a = builder.add_lookup_from_index(initial_a, lut_index);
    let output_b = builder.add_lookup_from_index(initial_b, lut_index);

    builder.register_public_input(output_a);
    builder.register_public_input(output_b);

    let data = builder.build::<C>();

    let mut pw = PartialWitness::new();

    pw.set_target(initial_a, F::from_canonical_u16(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_u16(look_val_b))?;

    let proof = data.prove(pw)?;
    assert_eq!(
        proof.public_inputs[0],
        F::from_canonical_u16(lut_fn(look_val_a))
    );
    assert_eq!(
        proof.public_inputs[1],
        F::from_canonical_u16(lut_fn(look_val_b))
    );

    data.verify(proof)
}

#[test]
fn test_many_lookups_on_big_lut() -> anyhow::Result<()> {
    init_logger();

    let config = CircuitConfig::standard_recursion_config();
    let mut builder = CircuitBuilder::<F, D>::new(config);

    let inputs: [u16; LUT_SIZE] = core::array::from_fn(|i| i as u16);
    let lut_fn = |inp: u16| inp / 10;
    let lut_index = builder.add_lookup_table_from_fn(lut_fn, &inputs);

    let inputs = (0..LUT_SIZE)
        .map(|_| {
            let input_target = builder.add_virtual_target();
            _ = builder.add_lookup_from_index(input_target, lut_index);
            input_target
        })
        .collect::<Vec<_>>();

    let initial_a = builder.add_virtual_target();
    let initial_b = builder.add_virtual_target();

    let look_val_a = 51;
    let look_val_b = 2;

    let output_a = builder.add_lookup_from_index(initial_a, lut_index);
    let output_b = builder.add_lookup_from_index(initial_b, lut_index);
    let sum = builder.add(output_a, output_b);

    builder.register_public_input(sum);

    let data = builder.build::<C>();

    let mut pw = PartialWitness::new();

    for (i, t) in inputs.into_iter().enumerate() {
        pw.set_target(t, F::from_canonical_usize(i))?
    }
    pw.set_target(initial_a, F::from_canonical_u16(look_val_a))?;
    pw.set_target(initial_b, F::from_canonical_u16(look_val_b))?;

    let proof = data.prove(pw)?;
    assert_eq!(
        proof.public_inputs[0],
        F::from_canonical_u16(lut_fn(look_val_a) + lut_fn(look_val_b))
    );

    data.verify(proof)
}

fn init_logger() {
    #[cfg(feature = "std")]
    {
        LOGGER_INITIALIZED.call_once(|| {
            let mut builder = env_logger::Builder::from_default_env();
            builder.format_timestamp(None);
            builder.filter_level(log::LevelFilter::Debug);

            builder.try_init().unwrap();
        });
    }
}