TASK DEFINITION: We would like you to assess the QUALITY of each of the following argument (discussing Death Penalty) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of death penalty. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of death penalty.
PROBLEM: Can life imprisonment for a definite yes, prevent a murderer from killing again?

SOLUTION: Valid

PROBLEM: Many people contend - and prove - that it's more costly to execute a man or to keep a man on deathrow than it would be to keep him in prison for life.

SOLUTION: Valid

PROBLEM: fit at all within the principles of the civilized society those who believe in

SOLUTION:
Invalid