Zero sums: the final cut

You have already done the heavy lifting in proving that x + y = 0 => y = 0. If you would like to take this result to its logical conclusion, you could try this optional bonus problem.

Hints: Remember that you can turn the == into two conditionals. Also it turns out that (A => B) & (A => C) => (A => B & C).

Where to go from here?

Some ideas:

• Looking under the hood
• Core concepts
• Advanced topics
• Theory