Neat. Great to see old-school _actual analysis_, I was worried when I read 'LLM' in the text. Instead, I learned something -- the Laplace operator. The OP's exp

Neat. Great to see old-school _actual analysis_, I was worried when I read 'LLM' in the text. Instead, I learned something -- the Laplace operator. The OP's explanation is considerably easier to understand than Wikipedia's :)