Fixed small typo in tutorial 01-21
@@ -157,7 +157,7 @@ first case, we see that `?X` is greater than or equal to 10, so the second rule
applied, rewriting the symbolic integer to the concrete integer 5. In the
second case, we see that the second rule did not apply because `?X` is less
than 10. Moreover, because of the `ensures` clause on the first rule, we know
-that `?X` is not zero, therefore the second rule will not apply a second time.
+that `?X` is not zero, therefore the first rule will not apply a second time.
If we had omitted this constraint, we would have ended up infinitely applying
the first rule, leading to `krun` not terminating.
