At: formula imp left sound112111121 1. concl: Formula List 2. M: Formula List 3. N: Formula List 4. q: Formula 5. r: Formula 6. a: Assignment 7. a |= < M @ (qr.N),concl > 8. a |= < r.(M @ N),concl >
a |= < M @ N,q.concl > a | < M @ N,q.concl > By: Choose [1] Generated subgoal: