N TPL DOUG LENAT CS 144A PROBLEM 4 TOTAL PATH LENGTH IN BINARY TREES 8 21 ( ( ( ( ( * ) * ( * ) ) * ) ) ) * ) * ) N TPL DOUG LENAT CS 144A PROBLEM 4 TOTAL PATH LENGTH IN BINARY TREES 50 506 ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( ( * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ) * ( * ) ) * ) * ) * ) * ) * ) ) ) ) ) * )