function_allows_missed.0rx

@type interface Type1 {}

@value interface Type2 {}

@value interface Type3 {}

concrete Type4<#x> {
  #x requires Type2
  #x allows Type3
  #x defines Type1

  @type something<#y>
    #y requires Type2
    #y defines Type1
  () -> (Type4<#y>)
}