Stuart contracts to act in a comedy for Charlotte and to comply with all theater regulations for four seasons. Charlotte promises to pay Stuart $$1,800$ for each performance and to allow Stuart one benefit performance each season. It is expressly agreed "Stuart shall not be employed in any other production for the period of the contract." Stuart and Charlotte, during the first year of the contract, have a terrible quarrel. Thereafter, Stuart signs a contract to perform in Elaine's production and ceases performing for Charlotte. Charlotte seeks

a$.$ to prevent Stuart from performing for Elaine and

b$.$ to require Stuart to perform his contract with Charlotte. What result? Explain.