use aiken/collection/list use cardano/transaction.{Output, Transaction} validator foo { spend( _datum: Option, _redeemer: Void, _ref: Data, transaction: Transaction, ) { expect Some(_) = list.find(transaction.outputs, fn(_) { True }) let _ = find_stuff(transaction) True } else(_) { fail } } fn find_stuff(transaction: Transaction) -> Output { expect Some(stuff) = list.find(transaction.outputs, fn(_) { True }) stuff }