Prawidłowy in English:

I had a valid visa, so I was allowed to enter the country.

Is it valid to say that all men are created equal?

This is a valid point of view.

It's valid until March thirty-first, nineteen-ninety-seven.

How long is this visa valid?

Your ticket is invalid!

You ought to think over whether the premise is valid or not.

His theory is widely accepted as valid.

this document isn't valid

Is your driving licence still valid?

One must have a valid ticket if one wishes to travel on a public transport.

valid driving licence

valid here as well

have you got a valid passport?

With all due respect, I think they both had valid points.