In this paper, functorial languages with the following characteristic are investigated: if two functor-argument structures occur in at last one common functorial context, then they are intersubstitutable on arguments' positions in all elements (sentences) of a language. We prove learnability of the class of all such languages (in the model of Gold). Since our class has infinite elasticity, we could not employ a widely used method of learnability proving. Instead, we adopted Buszkowski's discovery procedure, based on unification.
['Jacek Marciniec']
Tarski's principle, categorial grammars and learnability