16, suppose that h is a nonempty subset of a group g with the prop- erty that if a and b belong to h then a b belongs to h. prove or disprove that this is enoug

16, Suppose that H is a nonempty subset of a group G with the prop- erty that if a and b belong to H then a b belongs to H. Prove or disprove that this is enough to guarantee that H is a subgroup of G. ha. theaa emantc of