当事人的一方 meaning in English

one of the parties

The constitutive requirement for the substantial breach is the practical action of fundamental breach , which must have common breach character . in other words , the essential requirements the violation of the contract terms and its harmful consequence for the creditor and there is no need to require the subjective elements of the doer , which is the constitutive requirement of contract breach
根本违约是对违约行为的一种分类，它首先是一种违约行为，因而它也应具备一般违约行为的构成要件：一是当事人之间存在有效的合同关系，二是当事人的一方或双方实施有违返合同义务的行为。