Its obvious he means standard library by 'API'. Also the type returned doesn't need to be an integer, or even a number. If you need to write a min function th

Its obvious he means standard library by 'API'. Also the type returned doesn't need to be an integer, or even a number. If you need to write a min function then the type merely needs to form a partially ordered set. A string could fulfill this requirement - simply compare an integer representation of the first character if they're equal move on to the following character. Alphabetical ordering, taught to children at all good primary schools, is a restricted version of this comparison algorithm.