采用合同书形式订立合同，在签字或者盖章之前，当事人一方已经履行主要义务

采用合同书形式订立合同，在签字或者盖章之前，当事人一方已经履行主要义务，对方接受的，该合同成立。

結果 (英文) 1:

Written form contract prior to signing or sealing, the other party has fulfilled key obligations, is accepted, the contract is formed.

結果 (英文) 2:

A contract is a contract is concluded, signed or sealed before, if one party has performed its main obligation and the other accepted, the contract is established.

結果 (英文) 3:

Contract form contract, in the form of signature or seal, the parties have to fulfill the main obligations, the other party accepted, the contract was established.