@value interface Type0 { }

@value interface Type1 {
  refines Type0
}

@value interface Type2 {
  refines Type1
}

concrete Type4 {
  defines Defined<Type4>
}

@type interface Defined<#x> { }

@value interface Interface0<|#x> { }

@value interface Interface1<#y|> { }

@value interface Interface2<#y> {
  refines Interface0<#y>
  refines Interface1<#y>
}

@value interface Interface3<#y> {
  refines Interface0<#y>
  refines Interface1<#y>
}