Declare invalid and Tack on

Tack on and declare invalid are semantically related. In some cases you can use "Tack on" instead a verb phrase "Declare invalid".

Tack on verb - To join (something) to a mass, quantity, or number so as to bring about an overall increase.

Declare invalid and tack on are semantically related. Sometimes you can use "Declare invalid" instead a verb "Tack on".