I'm corrently trying to study Constructive Analysis, using the book 'Foundations of Constructive Analysis' by Erret Bishop, and I have the following problem:
"Construct a set A such that x = y for all elements x and y of A, but A is not subfinite or void."
I know what needs to be done, I need to find a "fugitive property of the natural numbers", a Brouwer's trick using unsolvable problems to generate sequences, but I don't find anywhere the definition of a "void set", how can a guarantee that a set is "not a void" in a constructive way?
"Construct a set A such that x = y for all elements x and y of A, but A is not subfinite or void."
I know what needs to be done, I need to find a "fugitive property of the natural numbers", a Brouwer's trick using unsolvable problems to generate sequences, but I don't find anywhere the definition of a "void set", how can a guarantee that a set is "not a void" in a constructive way?
