# Math Help - Boolean Algebra Help

1. ## Boolean Algebra Help

I am trying to prove the following is a tautology using boolean algebra. I have proved it is using a truth table. I have to state which rule is used at each step.

$(a \Rightarrow b) \vee a$

Below is my attempt, how's it look?

$(a \Rightarrow b) \vee a = (\neg a \vee b) \vee a, (Rewriting \Rightarrow)$
$= (\neg a \vee a) \vee b, (Associativing)$
$= T \vee b, (Negation (i))$
$= T, (Absorbtion)$

2. Looks good to me.

(Unless its a technical word I have seen before, the correct spelling is "absorption".)