  The notions of CR set is intimately related with the generalized van der
Waerden's theorem. In this article, we prove the product of two CR sets is
again a CR set. This answers [Question 4.2., N. Hindman, H. Hosseini, D.
Strauss, and M. Tootkaboni: Combinatorially rich sets in arbitrary semigroups,
Semigroup Forum, 107 (2023), 127-143.] . We use combinatorial arguments to
prove our result.
