Where is the Gödel-point hiding: Gentzen’s Consistency Proof of 1936 and His Representation of Constructive Ordinals

This book explains the first published consistency proof of PA. A notable aspect of the proof is the representation of ordinal numbers that was developed by Gentzen. The topic should interest researchers and students who work on proof theory, history of proof theory or Hilbert's program and who do not mind reading mathematical texts.?