Assume t0 < t1
Original: NOT(NOT(Mainstream(t0))) ==> NOT(Succesful(t1))
Contrapositive: Successful(t1) ==> NOT(Mainstream(t0))
Edit: Small edit for clarity and spelling.
Assume t0 < t1
Original: NOT(NOT(Mainstream(t0))) ==> NOT(Succesful(t1))
Contrapositive: Successful(t1) ==> NOT(Mainstream(t0))
Edit: Small edit for clarity and spelling.