Merkle Proof AccountInfo

AliceAccountInfo.js

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NODE = 'https://d3rmzi6ltfh1jy.cloudfront.net'
GENERATION_HASH = '6C1B92391CCB41C96478471C2634C111D9E989DECD66130C0430B5B8D20117CD';

nem = require("/node_modules/symbol-sdk");
sha3_256 = require('/node_modules/js-sha3').sha3_256;

repo = new nem.RepositoryFactoryHttp(NODE, nem.NetworkType.TEST_NET,GENERATION_HASH);
accountRepo = repo.createAccountRepository()
stateProofService = new nem.StateProofService(repo);

alice = nem.Account.generateNewAccount(nem.NetworkType.TEST_NET);
"http://faucet-0.10.0.x-01.symboldev.network/?recipient=" + alice.address.plain() +"&amount=2"

//ノードからAliceのマークル証明ツリーを取得
proof = await stateProofService.accountById(alice.address).toPromise();

//クライアント側でAliceのAccountInfoのハッシュを生成（検証のため一部ノードから取得）
aliceInfo = await accountRepo.getAccountInfo(alice.address).toPromise();
hasher = sha3_256.create();
aliceInfoHash = hasher.update(aliceInfo.serialize()).hex().toUpperCase();

//aliceInfo stateHashが等しいことを確認
aliceInfoHash === proof.stateHash

//stateHash が merkleTreeのleaf valueと等しいことを確認
proof.stateHash === proof.merkleTree.leaf.value;

//leafHashを算出
hasher = sha3_256.create();
leafHash = hasher.update(nem.Convert.hexToUint8(proof.merkleTree.leaf.encodedPath + proof.merkleTree.leaf.value)).hex().toUpperCase();

//leafの一つ上のbranchを取得
branchLength = proof.merkleTree.branches.length;
proof.merkleTree.branches[branchLength - 1];

//branch.links(keys?)の内部にleafHashが含まれることを確認
links = proof.merkleTree.branches[branchLength - 1].links
merkleTreeBranchLink = links.find(_ => _.link === leafHash)

console.log(merkleTreeBranchLink.bit)

bitって何？？
仮説
aliceAccountInfoの存在検証についてbitが何であるかを知る必要はない。
proof.merkleTree.branchesの中にleafHashが含まれてさえいればよい？