Disjunction introduction

Disjunction introduction or Addition is a valid, simple argument form in logic:


 * A.
 * Therefore, A or B.

or in logical operator (sequent) notation:
 * $$ A \vdash A \or B $$

The argument form has one premise, A, and an unrelated proposition, B. From the premise it can be logically concluded that either A or B is true, or both are true.

Here is an example of such an argument:


 * Socrates is a man.
 * Therefore (either or both of, but in this case probably only one of:) Socrates is a man, or pigs are flying in formation over the English Channel.