EKAMPLE G 函数 Determine whether the function f from a, b, c, d to(1, 2, 3, 4, 5) with f(a)=4,f(b)=5,f(Cc)=1,andf(d)=3 is one-to-oneF u n c t i o n s 函 数 EXAMPLE 6 Determine whether the function f from {a, b, c, d} to (1, 2, 3, 4, 5) with f(a) = 4, f(b) = 5, f(c) = 1, and f(d) = 3 is one-to-one