default of a party
当事一方不履行责任
back out(of sth)withdraw from(an agreement,a promise,etc)
不履行（协议、承诺等）
repudiate a treaty, contract, vow, etc
不履行条约、 合同、 誓约等.
an inofficious testament [ will ]
不履行道德义务的遗嘱
liability for nonperformance of an obligation
不履行债务引起的责任
The penalty for nonperformance of contract is heavy.
不履行合同的罚款很重。
If a defendant fails to perform or delays the performance of his statutory duty, a fixed time shall be set by judgment for his performance of the duty.
被告不履行或者拖延履行法定职责的,判决其在一定期限内履行.
We'll never fail to meet our obligations [commitments].
我们绝不会不履行我们（承担）的义务。
You can't run out on the contract, or you could be taken to court.
你不能不履行契约，否则就送你上法庭。
The Distinction of Inactive Administration and Unfulfilled Administration;
行政不作为与行政不履行法定职责界定
The analysis of administrative omission and Non-performance of statutory duties
行政不作为与行政不履行法定职责辨析
Where the person concerned fails to carry it out within the time limit, the marshal shall execute it forcibly.
被执行人逾期不履行的，由执行员强制执行
You cannot trust him (or to him) to keep his promise.
你不能希望他履行诺言。
The firm was not able to meet its obligations.
公司不能履行其契约。
The trustee has a duty to act in person and not to delegate to others.
受托人有亲自履行的义务，并不得转托他人履行。
If the party required to perform first rendered non-conforming performance, the party who is to perform subsequently is entitled to reject its corresponding requirement for performance.
先履行一方履行债务不符合约定的，后履行一方有权拒绝其相应的履行要求。
if the obligation is delivery of immovable property, performance shall be at the place where the immovable property is located;
交付不动产的，在不动产所在地履行；
(vi) If the party responsible for the expenses of performance was not clearly prescribed, the obligor shall bear the expenses.
（六）履行费用的负担不明确的，由履行义务一方负担。