Minimax Search with Alpha-Beta Pruning

ALPHA-BETA(state, player, depth, alpha, beta) /* alpha is the highest score achievable by MAX along the path to state beta is the lowest score achievable by MIN along the path to state */ If the level is the top level, let alpha = -infinity, beta = +infinity If state is a terminal state, or if depth has reached the search limit:     apply evaluation function to state and return result If player is MAX:     Until all of state's children are examined with ALPHA-BETA or until     alpha is equal to or greater than beta:              Call ALPHA-BETA(child, MIN, depth+1, alpha, beta)              and note result           Compare the value reported to alpha; if reported value              is larger, reset alpha to the new value      Return largest value reported If player is MIN:     Until all of state's children are examined with ALPHA-BETA or until     alpha is equal to or greater than beta:              Call ALPHA-BETA(child, MAX, depth+1, alpha, beta)              and note result           Compare the value reported to beta; if reported value              is smaller, reset beta to the new value      Return smallest value reported