Admissible heuristic
= Admissible heuristic
{title2=$h(s)\le h^*(s)$}
A <heuristic function> bounded above by the minimum remaining goal cost $h^*(s)$. When no goal is reachable, take $h^*(s)=\infty$. Admissibility is a lower-bound guarantee, rather than a statement that the estimate is usually numerically accurate. Ignoring constraints can produce a <relaxation heuristic> because it enlarges the available solution set.