You don't need the 'goto double' line, execution is anyway going skip to 'double: left' making the line redundant Also say each step takes one unit of time, so

You don't need the 'goto double' line, execution is anyway going skip to 'double: left' making the line redundant Also say each step takes one unit of time, so one 'start' loop requires 3 units to go one unit of distance, whereas 'double' takes 3 units to go 2 units of distance, even if you use one left statement in the 'double' loop, robot will still move faster than the other as it will require only two units of time to go one unit of distance. :)