Consistent Heuristic - What does it mean for A heuristic to be inconsistent?

An inconsistent heuristic might return a value such as h(c)=2 for a child node c of a parent node p. If all operators have a cost of 1, the minimum total cost to reach the goal through c will be f(c) = g(c) + h(c) = (5 + 1) + 2 = 8. This lower limit, 8, is less restrictive than the lower limit from the parent.