Shenanigans with Roslyn and the C# type checker

ConfusingSyntaxError.cs

int a = 1, b = 2, c = 3;

System.Console.WriteLine(
  "{0} {1}",
   a < b,
   c > (1 + 2)
);

ExponentialCompilationTime.cs

using System;

class Program {
  static void Main() =>
    F(a =>
      F(b =>
        F(c =>
          F(d =>
            F(e =>
              F(f =>
                F(g =>
                  F(h =>
                    F(i =>
                      F(j =>
                        F(k =>
                          F(l =>
                            F(m =>
                              F(n =>
                                F(o =>
                                  F(p =>
                                    F(q =>
                                      F(r =>
                                        F(s =>
                                          F(t =>
                                            F(u =>
                                              F(v =>
                                                F(w =>
                                                  F(x => null)
                                                )
                                              )
                                            )
                                          )
                                        )
                                      )
                                    )
                                  )
                                )
                              )
                            )
                          )
                        )
                      )
                    )
                  )
                )
              )
            )
          )
        )
      )
    );
  static object F(Func<True, object> f) => null;
  static object F(Func<False, object> f) => null;
}
class True {}
class False {}

ExponentialCompilationTime2.cs

class Program
{
  static void Main() {
  
  }
}

class C<a, b, c, d, e, f>
{
  class I : C<I, I, I, I, I, I> { 
    I.I.I.I.I.I.I.I.I i;
  }
}