Level: Lib Thy Top: 1
Hypotheses:

  1. A :

  2. R : A List A List

  3. EquivRel(A List;x,y.x R y)

  4. x,y,z:A List. x R y (z @ x) R (z @ y)

  5. z : A List

  6. y : x,y:(A List)//(x R y)

Conclusion:

z@y x,y:(A List)//(x R y)

Applied Tactic: (Unfold `member` 0 THENM D 6 ...a)
Generated subgoals:

1. z@y1 = z@y2