Prova pela Contrapositiva

Introduction to Mathematical Logic Professor Maurício Carvalho Proof by Contrapositive Description: When proving that an implication is true, we can choose to prove that its contrapositive is true, since we know that the two implications are equivalent. In this video, we will discuss this important proof technique and provide some examples. Access more video lessons and all the material from the Mathematics Portal at http://matematica.obmep.org.br The rights to all material on this channel belong to the Institute of Pure and Applied Mathematics, and the total or partial use of the content is prohibited without prior written authorization from the aforementioned holder, except in the cases provided for in current legislation. The rights over all the material in this channel belong to the Instituto de Matemática Pura e Aplicada, and it is forbidden to use all or part of it without prior written authorization from the aforementioned holder, except in the cases prescribed in the current legislation.