>>12418316>Pure undergrad idiocy. It's dubs IFF (if and only if) the last two digits are the same. Trips aren't in the same equivalence class.You do understand what 'if and only if' means, right?
1) If it's dubs, then the last two digits are the same.
2) If the last two digits are the same, then it's dubs.
If a number is an element of trips, its last three digits are the same.
If the last three digits are the same, then the last two digits are the same.
If the last two digits are the same, then it's dubs by (2).
