@Majkawscianie "y" is a letter. It can represent vowels and consonants in different contexts. In "rhythm" it obviously represents a vowel /ɪ/. In "Yorkshire" it represents a consonant /j/.
@ChrisTCollins I also like Marcus Tomalin's article "Reconsidering recursion in syntactic theory" on this topic. And his book "Linguistics and the Formal Sciences" is also great
@abenitezburraco Can someone send me the pdf?
The claim about a transformational component sounds strange, because I thought that transformational grammars == mildly context-sensitive phrase structure grammars == (mildly) non-projective dependency grammars