Markov's Principle - Weak Markov's Principle

Weak Markov's Principle

A weaker form of Markov's principle may be stated in the language of analysis as

This form can be justified by Brouwer's continuity principles, whereas the stronger form contradicts them. Thus it can be derived from intuitionistic, realizability, and classical reasoning, in each case for different reasons, but this principle is not valid in the general constructive sense of Bishop.