My father underwent surgery for kidney stones.

In order to solve this quantum mechanics problem, we need to find the eigenfunction.

The door won't open because this hinge is broken.

I want to go to Sweden.

He is passionate about researching pure mathematics.

Recently, I've been feeling heavy-headed due to lack of sleep.

I look forward to going to the sea for a swim with my family during the summer vacation.

Abstract algebra is a branch of mathematics that studies algebraic structures.

Abstract algebra is a field of mathematics that studies algebraic structures in an abstract way.

This eigenfunction is one of the fundamental concepts of quantum mechanics.