CSP heuristics to help avoid redundancy while checking values for constraint inconsistency?
These are known as variable ordering heuristics.  One standard one is &quot;fail first&quot;.  See the &quot;dom&quot; heuristic, i.e., try first the variable with the fewest number of possible values, or &quot;dom+deg&quot;, where ties are broken by choosing the variable that participates in the smallest number of constraints.  That would handle the case you list as desired.