A chess engine needs to make a move, search deeper, then unmake the move. In a normal language, local variables or a call stack handle this naturally. TeX has grouping-based scoping, but the engine’s design uses global state throughout (every \count register, every \newcount variable, every \newif flag is global).
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，这一点在新收录的资料中也有详细论述
repeat penalty = disabled or 1.0，推荐阅读新收录的资料获取更多信息
Любовь Ширижик (Старший редактор отдела «Силовые структуры»)，这一点在新收录的资料中也有详细论述