covering sieve造句

• A continuous functor sends covering sieves to covering sieves.
• A continuous functor sends covering sieves to covering sieves.
• To define the "'discrete topology "', we declare all sieves to be covering sieves.
• A covering sieve or covering family for this site is said to be " strictly universally epimorphic ".
• A topology which is less fine than the canonical topology, that is, for which every covering sieve is strictly universally epimorphic, is called "'subcanonical " '.
• The covering sieves and covering families are almost exactly the same; the only difference is that now all the maps involved commute with the fixed maps to " X ".
• Say that { " X " ? ?! " X " } is a covering family if and only if the sieve that it generates is a covering sieve for the given topology.
• If " J " is the topology defined by a pretopology, and if " u " commutes with fibered products, then " u " is continuous if and only if it sends covering sieves to covering sieves and if and only if it sends covering families to covering families.
• If " J " is the topology defined by a pretopology, and if " u " commutes with fibered products, then " u " is continuous if and only if it sends covering sieves to covering sieves and if and only if it sends covering families to covering families.