Фоменко Т. Н. - Математический анализ. Часть 1 - Лекция 3

The lecture begins with an introduction at 00:00:10, then covers the concepts of sum and product of real numbers and the inverse real number at 00:02:14. It proceeds with proofs of the correctness of the definitions of sum, product, and inverse at 00:14:39, 00:31:46, and 00:52:47 respectively, and concludes with properties of comparison, addition, and multiplication of real numbers at 01:02:50.