@value interface Base {}

@value interface Child1 {
  refines Base
}

@value interface Child2 {
  refines Base
}

@value interface Inherit<#x|> {}

@value interface Parent1 {
  refines Inherit<Child1>
}

@value interface Parent2 {
  refines Inherit<Child2>
}

concrete Test {
  refines Parent1
  refines Parent2
  refines Inherit<Base>
}