1.同じ「壁」が単数だったり複数だったり("Killing Commendatore," Haruki Murakami (ハードカバー)より)
"Just that empty cylindrical space surrounded by the same stone wall" (p.487、単数、数が重要ではなく、「壁」という概念に意味があるから?)
"I had last seen it leaning against the wall of the pit" (同頁、同上、+英文法で言う定冠詞の「代表」用法?"a wall of the pit"とすると特定の壁に意味がありそうな?)
"You can feel how intimidating the height of those walls is" (p. 488、複数、自分を囲む各方向の壁という視点、主観、心理的な?)
2.to不定詞の否定におけるnotの位置。
"I waited patiently for things to not work out between her and this handsome boyfriend"(p. 333、 "not to work out"でも同じ?