inputs: hypothesis: Steve Jobs is the co-founder of Apple. premise: More than three months into a medical leave from Apple Inc., Chief Executive Steve Jobs remains closely involved in key aspects of running the company, say people familiar with the matter. Chief Operating Officer Tim Cook runs the day-to-day operations at Apple, these people say. But Jobs has continued to work on the company's most important strategies and products from home, they say. He regularly reviews products and product plans, and was particularly involved in the user interface of the new iPhone operating system that Apple unveiled last month, these people say.