1. The problem statement, all variables and given/known data Find a collection of well-formed formulas Ʃ such that Ʃ has no independent equivalent subset. 2. Relevant equations N/A 3. The attempt at a solution So far I have been able to show that Ʃ must be infinite. However, after this, I get stuck. Could anyone give me a hint on how to construct such a Ʃ? Thanks!