C# Syntax lambdas with curly braces

Question

delegate int AddDelegate(int a, int b);
AddDelegate ad = (a,b) => a+b;


AddDelegate ad = (a, b) => { return a + b; };

The two above versions of AddDelegate are equivalent. Syntactically, why is it necessary to have a semicolon before and after the } in the second AddDelegate? You can a compiler error ; expected if either one is missing.

Answer 1

Maybe this will make it clearer:

AddDelegate ad = (a, b) =>
                 {
                     return a + b;
                 };

These semicolons effectively are for different lines.