Topology Proceedings 8 (1983) pp. 195-212: WEAK CONFLUENCE AND MAPPINGS TO ONE-DIMENSIONAL POLYHEDRA
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Topology Proceedings
The co-elementary hierarchy is a nested ordinalindexed sequence of classes of mappings between compacta, with each successor level being defined inductively from the previous one using the topological ultracopower construction. The lowest level is the class of continuous surjections; and the next level up, the co-existential maps, is already a much more restricted class. Co-existential maps are...
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