Legal Principle: Every agreement by which anyone is restrained from exercising a lawful profession, trade or business of any kind, to that extent is void.
Factual Situation: A agreed to become assistant for three years to B who was a doctor practicing at Zanzibar. It was agreed that during the term of the agreement, A was not to practice on his own account in Zanzibar. At the end of one year, A ceased to act as B's assistant and began to practice on his own account.
Issue: Can A be restrained?