A proposal is revoked:
1. By the communication of notice of revocation by the proposer to the other party, in the manner prescribed by Sections 1581 and 1583, before his acceptance has been communicated to the former;
2. By the lapse of the time prescribed in such proposal for its acceptance, or if no time is so prescribed, the lapse of a reasonable time without communication of the acceptance;
3. By the failure of the acceptor to fulfill a condition precedent to acceptance; or,
4. By the death or insanity of the proposer.