This filter rules out (a, b). No case is assigned to the subject position of the complement of seems; only by moving to the subject position of the matrix clause can John satisfy the case filter: it is assigned case there.
a * it seems [ John to be angry ]
b John seems [ ti to be angry ]
More recently, the case filter has been reduced to the visibility condition.
- Chomsky, Noam A. 1981. Lectures on Government and Binding. Dordrecht:Foris.
- Chomsky, Noam A. 1986. Knowledge of language: its nature, origin and use. Praeger, New York.