Kya Hai Doctrine of Pith and Substance?

Bhai log, yeh term textbooks mein toh theek se explain kiya jata hai, lekin jyada deep mein jab baat karein, toh problem ho jati hai. Meri understanding hai ki yeh doctrine humein aadhar shasan ki vyavastha kiya ki, kya koi constitutional power ki overreach ho gayi hai ya nahi. Lekin agar aapko pata bhi nahi hai, toh aapko lagta hai ki yeh kuch aur hi hai. Koi bhai, aap share karenge aapko clear real-world example toh, jo aapne AILET ki preparation mein diya hai? Ya phir koi bhai, aapko lagta hai ki textbooks mein kaha gaya hai, wah sach hai ya nahi. Jaldi bataein, bhai.