Inversions in conditionals

In certain conditional sentences we can omit “if” and invert the subject and auxiliary verb as if it were a question

auxiliary + subject + verb

It is a more formal form but the meaning is exactly the same.

Normal form

Inversion

If he should call, let me know. Should he call, let me know.
If he were to ask for more money, it would be a problem. Were he to ask for more money, it would be a problem.
If she had studied more, she would have passed the exam. Had she studied more, she would have passed the exam.