livecode-bot

object unsoundMini extends App {
  trait A { type L >: Any}
  def upcast(a: A, x: Any): a.L = x
  val p: A { type L <: Nothing } = null
  def coerce(x: Any): Nothing = upcast(p, x)
  coerce("Uh oh!")
}

livecode-bot

class UnsoundSpec {
  static class Constrain<A, B extends A> {}
  static <A,B extends A>
  A upcast(Constrain<A,B> constrain, B b) {
    return b;
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;
    return upcast(constrain, t);
  }

livecode-bot

(define anyo
  (lambda (g)
    (conde
      (g)
      ((anyo g)))))

livecode-bot

(define ,A
  (lambda (xs ys)
,C))

livecode-bot

class Unsound {
  static class Constrain<A, B extends A> {}
  static class Bind<A> {
    <B extends A>
    A upcast(Constrain<A,B> constrain, B b) {
      return b;
    }
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;

livecode-bot

class Unsound {
  static class Constrain<A, B extends A> {}
  static class Bind<A> {
    <B extends A>
    A upcast(Constrain<A,B> constrain, B b) {
      return b;
    }
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;

livecode-bot

class Unsound9<U,T> {
  static class Type<A> {
    class Constraint<B extends A> extends Type<B> {}
    <B> Constraint<? super B> bad() { return null; }
    <B> A coerce(B b) {
      return pair(this.<B>bad(), b).value;
    }
  }
  static class DependentSum<T> {
    Type<T> type;

livecode-bot

class UnsoundSpec {
  static class Constrain<A, B extends A> {}
  static <A,B extends A>
  A upcast(Constrain<A,B> constrain, B b) {
    return b;
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;
    return upcast(constrain, t);
  }

livecode-bot

class UnsoundSpec {
  static class Constrain<A, B extends A> {}
  static <A,B extends A>
  A upcast(Constrain<A,B> constrain, B b) {
    return b;
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;
    return upcast(constrain, t);
  }

livecode-bot

class Unsound {
  static class Constrain<A, B extends A> {}
  static class Bind<A> {
    <B extends A>
    A upcast(Constrain<A,B> constrain, B b) {
      return b;
    }
  }
  static <T,U> U coerce(T t) {
    Constrain<U,? super T> constrain = null;