def sub_alias_issues
import cli@0.2.0.0/cli.bend as Cliimport Base
1894def sub_alias_issues(aliases: List<&2, String>, +at: String,
1895 +seen: List<&2, Seen>) -> List<&2, Problem>:
1896 match aliases:
1897 case Nil{}: Nil{}
1898 case +name <> tail:
1899 List.append(&2, Problem,
1900 sub_alias_issue(name, at, seen),
1901 sub_alias_issues(tail, at, SeenSubAlias{name} <> seen))