What is mirror principle and it’s principles?

For this question, I'm assuming you're referring to land law in the United Kingdom and the topic of registration. The Mirror Principle holds that the land registry accurately reflects all facts about the land and the title to it. To be relied on, the register must be an accurate reflection of the state of the land at any given time. The presence of overriding interests is the key weakness in this (also known as the "crack in the mirror"). The following are the major authorities: • Paragraph 2 of Schedule 3 of the LRA of 2002 (overriding interests) • Sections 23, 26, and 29 of the LRA of 2002 (owner's powers, security of buyers/disponees, and effect of registered dispositions) • Cann v Abbey National Building Society (what actions give rise to actual occupation and therefore a basis of an overriding interest) • Boland v Williams & Glyn's Bank (Overreaching takes precedence over overriding interests; overreaching occurs when a buyer pays the purchasing price to two trustees.) When purchasers pay money to two or more trustees, any vulnerability they may have is eliminated.)