Subjacency Violations: Multiple Wh-extraction

In the case of indirect questions, subjacency follows from the principle that a given tree cannot contain more than one wh-element. Extraction out of an indirect question is ruled out because a sentence like (45) would have to be derived from the adjunction of do you wonder into who_i who_j e_j loves e_i, which is an ill-formed elementary tree.^8.9

(44)0(44

(45)

Who_i do you wonder who_j e_j loves e_i ?