An excellent resource about SGI systems, from the early Motorola 68000-based
Lets assume, we would double, triple, quadruple, etc. Bobs world and stack these copies on top of each other. Bob would never notice, as long as each copy is just a “shallow” copy, meaning that each movement in the fundamental domain (the original world) is mirrored in the copies. In this case, we would have a covering space of Bobs world, and the original world would be the base space.
。关于这个话题，PDF资料提供了深入分析
刚到浙江工作，有人请习近平同志谈谈“施政纲领”，他笑着说：“我刚刚来，还没有发言权。到时候，我是要说的。”
在未根据救助方的要求对获救的船舶或者其他财产提供满意的担保以前，未经救助方同意，不得将获救的船舶和其他财产从救助作业完成后最初到达的港口或者地点移走。