@value interface Interface1<|#x> { }

@value interface Interface2<#y|> { }

@value interface Interface3<#z> {
  refines Interface1<Type1>
}

@value interface Interface4<#x|#y|#z> { }

@value interface Type0 { }

@value interface Type1 {
  refines Type0
}

@value interface Type2 {
  refines Type1
}