像 (数学)
↑ Blyth 2005, p. 5
↑ Jean E. Rubin (1967), Set Theory for the Mathematician, Holden-Day, p. xix, ASIN B0006BQH7S
1 2 Kelley (1985), p. 85
↑ Equality holds if B is a subset of Im(f) or, in particular, if f is surjective. See Munkres, J.. Topology (2000), p. 19.
↑ Equality holds if f is injective. See Munkres, J.. Topology (2000), p. 19.