1. Without the signature of the leader, it cannot be proved that the agreement was signed by the leader, so it is invalid.

2, signature, that is, write your own name, especially to express agreement, recognition, responsibility or obligation. There are more interpretations of signature, such as digital signature, artistic signature and so on. Or a star's meaningful signature, also called signature. Signature is a kind of signature, because the signature is used the most, so the signature is often corrupted into a signature. Traditionally, signature is not synonymous with signature. The signature should be readable, but the signature is unnecessary. People have certain requirements for signature, and the signature represents the consent, which has legal effect and gives the document authenticity in law.