If you plasticize your birth certificate, it will make it invalid.
The premise behind your theory is improbable; therefore, your theory is invalid.
In March of 1990, the Soviet government ruled that Lithuania’s declaration of independence was invalid, and that Soviet law was still in force in the Baltic republic.
According to independent vote monitors, Serbia’s first presidential elections since Slobodan Milosevic’s removal from power were considered invalid because of low turnout.
If the certificate was invalid you would receive a warning message saying that the site you are entering has not renewed their security certificates.
A request is denied if the access key is invalid.
If any of the answers are untrue the contract becomes invalid and the company does not have to pay out in the event of the claim.
If you attempt to enter invalid data, the program beeps.