Not a butterfly
"I think we look like a butterfly when asleep." He said.
"What? No!" She said.
"My head's there, your butt is here and we are curled onto our own sides. Of course, we look like a butterfly."
She picked up her brush, sat in front of the canvas and spent over 45 days, to create a theorem.
"Hence proved!" She said.
"Butterfly!" He said.