Abstraction heuristic
= Abstraction heuristic
{title2=$h_{\mathrm{abs}}$}
Map original states to simpler abstract states, include every projected original transition at no greater cost, and map original goals to abstract goals. An original goal-reaching <graph path> then projects to an abstract goal-reaching walk, so the exact abstract distance is an <admissible heuristic>. A <pattern database> stores such distances for repeated lookup.