| 释义 |
surjection Math.|sɜːˈdʒɛkʃən|
[f. sur-, after injection 5.]
An onto mapping.
1964W. J. Pervin Found. Algebraic Topology i. 11, f is a surjection or epimorphism. 1979Q. Jrnl. Math. XXX. 358 The well-known surjection from tensor powers of Pab to lower central factors of P.
Hence surˈjective a., that is a surjection.
1964S.-T. Hu Elem. Gen. Topology i. 7, f:X → Y is surjective if, for every point y in Y, there exists at least one point x in X such that f(x) = y. 1968D. L. Clarke Analytical Archaeol. ix. 360 The taxa of one aspect are related to the taxa of the other aspects as elaborate injective and surjective mappings. 1979Proc. London Math. Soc. XXXVIII. 209 We recall some facts..about the abelian group A(G)... If F is a finite subgroup of G, then A(G) → A(F) is surjective. |