# Pairwise disjoint set proof (help)

hello,

I really dont know how to proceed here, since I dont know very much about sets/family.

I want to prove that if Ð is a family of pairwise disjoint sets, and Ŧ is a subset of Ð, prove that Ŧ is also a family of pairwise disjoint sets.

William

matt grime
Homework Helper
if x and y are elements of T, then they are elements of D. So what is xny? (n means intersection)

if x and y are elements of T, then they are elements of D. because T is a subset of D.

However, xny will be empty set, because they are also elements of D, and D is pairwise disjoint.

T is also pairwise disjoint.

Like that?

Precisely.

Thanks guys!