try:
    var <- call "me" ("", "") []
    ap var.$.value data
    par:
        par:
            call "other1" ("set", "") [data]
        |
            call "other2" ("insert", "") [data]
    |
        ap "key" key
        $values <- call "other3" ("", "") [key, data]
        fold $values i:
            try:
                j <- call "other2" ("insert", "") [i]
                call "other3" ("report", "") [j]
            catch:
                fail 3 "fail to fold"
            next i
catch:
    par:
        rep <- call "other1" ("report", "error") [%last_error%]
        call "other2" ("report", "error") [%last_error%, rep]
    |
        call "other3" ("report", "error") [%last_error%]
