Two subclasses P(n)(alpha) and Q(n)(alpha) of certain analytic functio
ns in the open unit disk U are introduced. For p(z) is-an-element-of P
(n)(alpha) and delta(n) greater-than-or-equal-to 0, the delta(n)-neigh
borhood N(delta)n (p(z)) of p(z) is defined. For P(n)(alpha), Q(n)(alp
ha), and N(delta)n (p(z)), we prove that if p(z) is-an-element-of Q(n)
(alpha), then N(1-alpha)delta(n)(P(z)) subset-of P(n)(alpha).