If one of my students asked me that question I would say, "What a great question! It shows that you are thinking. Here is what the regs say..."
However, if the assistant chief flight instructor with over 5,000 hours asks me that same question because he doesn't know the elementary regs about the topic, then I might consider moving out of fuel range of that school. And I don't know why you keep complaining about proof? Others have already posted all the regs you need.
I'm sorry for being blunt. To be honest, myself and others really thought you were kidding. We thought see and avoid, safety pilot requirements, and careless and reckless operation were common knowledge for "professional" pilots.
So, now that we know you are serious and not trolling, I'll start over-> That's a really good question! It shows that you are thinking. Here is what the regs say...
91.113(b)
91.109
91.13
Now if you'll excuse me, I have a U-Haul to pack.