pcase无法识别字符串匹配

我试图插入Latex命令或UTF-8符号 到缓冲区,但是 pcase 正在给我 "No Match" 选择时 "bigodot" 。

grafm 中预期我通过删除修改 UTF-8 符号,依据 将第一个单词放在第一个空格之前,只使用字符串 描述符 “bigodot” 用于 pcase 条款

(defun imprint (selector kmstr &optional grapheme)
  "Insert Latex Command or the equivalent UTF-8 grapheme."

  (if (or (not grapheme) (equal selector "Command"))
      (insert kmstr)
    (insert grapheme)))

;;-------------------------------------

(defun bigops (grafm seltr)
  "Binary Operations."

  (interactive
    (let ( (csel '("Symbol" "Command"))
           (cseq '("bigodot ⨀" "bigoplus ⨁︁" "bigotimes ⨂︁")) )

      (list
        (completing-read "Grapheme: " cseq nil t "bigcap ⋂")
        (completing-read "Selector: " csel nil t "Command")) ))

  (setq grafm (car (split-string grafm)))
  (message "Grafm: .%S." grafm)

  (pcase grafm
    ("bigodot" (imprint seltr "\\bigodot" "⨀"))
    ("bigoplus︁" (imprint seltr "\\bigoplus" "⨁︁"))
    ("bigotimes︁" (imprint seltr "\\bigotimes" "⨂︁"))
    (_  (message "%s" "No Match")) ))