C. Contract with exclusive agent

i. Anticipatory repudiation: Sam called agent after "contract" with Bob was "formed" and said he was terminating agent's services. Agent had a six month contract, substantially performed by putting ad in car collector magazine that Charlie saw and answered. Unambiguous communication to terminate contract = total breach by Sam.

For this part, I argued that the contract between Sam and Art was unilateral instead of bilateral and unilateral contracts becomes irrevocable when the other side starts to perform. I did not argue anticipatory repudiation because Art had already performed his duty at the time Sam attempts to revoke the contract.

Thoughts?