  For gravitational collapse, we observe a correspondence between region close
to past null infinity and region close to central singularity. In line with
this philosophy, we construct a new ansatz, with which we first present a
40-page self-contained proof of trapped surface formation in a far-from-center
region. A systematical approach with only signature for decay rates is used.
Then by a rescaling argument, we convert this result into a reproof and an
extension of a scale-critical theorem proved by An-Luk.
