  What is the proper explanation of intuitionistic hypothetical judgment, and
thence propositional implication? The answer is unclear from the writings of
Brouwer and Heyting, who in their lifetimes propounded multiple (sometimes
conflicting) explanations of the hypothetical judgment. To my mind, the
determination of an acceptable explanation must take into account its adequacy
for the expression of the bar theorem and, more generally, the development of
an open-ended framework for transcendental arguments in mathematics.

Logic in Computer Science;Logic