It remains to be seen whether Mr Thaler's book grows to be as admired as La Disparition (The Disappearance), which Georges Perec wrote in 1969 without using the letter "e". Mr Perec, who tried to expand literature by borrowing formal patterns from other disciplines such as mathematics and chess, followed it up with Les Revenantes (The Ghosts), in which the only vowel he used was "e".