# Heuristic function

Is there any way to prove that an admissible heuristic may not be consistent? Most proof I came across are through examples .Is there a generalized proof?

• What have you tried? Where did you get stuck? Do you have a specific instance of the problem that you weren't sure how to handle? One valid way to dis-prove "X is always true" is to exhibit one example where X isn't true, so it's not clear what you are asking -- it seems you already know of some counterexamples, so I can't tell what you are looking for.
– D.W.
Jul 21 '15 at 18:07
• A counterexample is a proof. Jul 21 '15 at 21:36

• @Alex_ban $2$ is a counterexample to the claim "all even numbers are squares". Jul 21 '15 at 22:39