Thread: Poincare's Theorem

Let H1 & H2 be subgroups of G. How can it be shown that if H1 & H2 have finite index in G then so the intersection of H1 & H2.

Originally Posted by thomas_donald

Let H1 & H2 be subgroups of G. How can it be shown that if H1 & H2 have finite index in G then so the intersection of H1 & H2.

Hint (acually the solution!!): for all