Formalising Regular Language Theory with Regular Expressions, Only
❈❤r✐st✐❛♥ ❯r❜❛♥
❑✐♥❣✬s ❈♦❧❧❡❣❡ ▲♦♥❞♦♥ ❥♦✐♥t ✇♦r❦ ✇✐t❤ ❈❤✉♥❤❛♥ ❲✉ ❛♥❞ ❳✐♥❣②✉❛♥ ❩❤❛♥❣ ❢r♦♠ t❤❡ P▲❆ ❯♥✐✈❡rs✐t② ♦❢ ❙❝✐❡♥❝❡ ❛♥❞ ❚❡❝❤♥♦❧♦❣② ✐♥ ◆❛♥❥✐♥❣
❙t ❆♥❞r❡✇s✱ ✶✾ ◆♦✈❡♠❜❡r ✷✵✶✶ ➊ ♣✳ ✶✴✶✽