chest for cxcy in chestsif abs(cx xabs(cy )distance abs(cx xelsedistance abs(cy yif distance smallestdistancewe want the closest treasure smallestdistance distance line uses the multiple assignment trick in for loop for examplethe assignment statement spameggs [ will assign to spam and to eggs because chests is list where each item in the list is itself list of two integersthe first of these integers is assigned to cx and the second integer is assigned to cy so if chests has the value [[ ][ ][ ]]cx will have the value and cy will have the value on the first iteration through the loop line determines which is largerthe absolute value of the difference of the coordinatesor the absolute value of the difference of the coordinates abs(cx xabs(cy yseems like much shorter way to say thatdoesn' itlines to assign the larger of the values to the distance variable so on each iteration of the for loopthe distance variable holds the treasure chest' distance from the sonar device but you want the smallest distance of all the treasure chests this is where the smallestdistance variable comes in whenever the distance variable is smaller than smallestdistancethen the value in distance becomes the new value of smallestdistance give smallestdistance the impossibly high value of at the beginning of the loop so that at least one of the treasure chests you found will be put into smallestdistance by the time the for loop has finishedyou know that smallestdistance holds the shortest distance between the sonar device and all of the treasure chests in the game the remove(list method the remove(list method will remove the first occurrence of value matching the passed in argument for exampletry entering the following into the interactive shellx [ remove( [