Piotr Hajłasz
= Piotr Hajłasz
{c}
Piotr Hajłasz authored notes on <functional analysis> developing <Banach spaces>, <Hilbert spaces> and the <Baire category theorem>. One application proves that a smooth real function is a <polynomial> if, at every point, at least one of its derivatives vanishes. The proof illustrates how a countable union of local conditions can force a global algebraic conclusion.<Functional Analysis by Piotr Hajłasz>[Proposition 8.3 and proof]{ref}