On a Problem concerning the Rule of Substitution for Functions in Begriffsschrift

Abstract
Our aim is to present a problem in Begriffsschrift related to the rule of  substitution for functions that leads to the formation of not-well-formed expression.
Keywords: Frege, Begriffsschrift, Rule of substitution for functions

on_rule_substitution

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https://gitlab.com/dedekindbr/meusartigos/tree/master/artigo1

https://gitlab.com/dedekindbr/meusartigos/repository/archive.zip?ref=master