Suppose that {e1,…,er+1} is a linearly independent set of distinct elements of a vector space V and {e1,…,er,fr+1,…,fm} spans V. Prove that fr+1,…,fm may be reordered, as necessary, so that {e1,…er+1,fr+2,…,fm} spans V.
Suppose that {e1,…,en} is a linearly independent set of distinct elements of V and that {f1,…,fm} spans V. Show that n⩽m.