> Aztec.nr API reference, v6.0.0 (mainnet and testnet). Index: https://docs.aztec.network/aztec-nr-api/mainnet/llms.txt

# Function accumulate_tx_effects_tree_root

Module: `noir_aztec::protocol::blob_data`

```rust
pub fn accumulate_tx_effects_tree_root(left_root: Field, right_root: Field) -> Field
```

Combines the tx effects tree roots of two adjacent subtrees of txs, as the rollup tree is walked upwards.

Unlike `accumulate_out_hash`, zero roots are NOT skipped: there are no padding txs, so every leaf is a real tx and the tree shape is a function of the number of txs alone. The separator differs from [`DOM_SEP__TX_EFFECTS_TREE_LEAF`](/aztec-nr-api/mainnet/protocol_types/constants/global.DOM_SEP__TX_EFFECTS_TREE_LEAF.md), so an internal node can never be confused with a leaf.