nit

csp/csp/scribblings/csp.scrbl

@@ -112,7 +112,7 @@ By the way, what if we had accidentally included @racket[c] in the last constrai
 (solve* triples)
 ]
 
-Nothing changes. Why not? Because of the existing @racket[valid-triple?] constraint, @racket[c] is necessarily going to be larger than @racket[a] and @racket[b]. So it always meets this constraint too. But generally, it's good practice to minimize constraints — no need for the ``belt and suspenders'' approach.
+Nothing changes. Why not? Because of the existing @racket[valid-triple?] constraint, @racket[c] is necessarily going to be larger than @racket[a] and @racket[b]. So it always meets this constraint too. It's good practice to not duplicate constraints between the same sets of variables — the ``belt and suspenders'' approach just adds work for no benefit.
 
 We should use @racket[solve*] with care. It can't finish until the CSP solver examines every possible assignment of values in the problem, which can be a big number. Specifically, it's the product of the domain sizes of each variable, which in this case is 40 × 40 × 40 = 64,000. This realm of possible assignments is also known as the CSP's @deftech{state space}. We can also get this number from @racket[state-count]: