Program Verification - the process of formal proving, that the Computer program does exactly what is stated in the program specification it was written to realize.

... both sides, getting
<math>x^2+\frac{b}{a}x+\frac{b^2}{4a^2}=-\frac{c}{a}+\frac{b^2}{4a^2}.</math>
The left side is now a perfect square; it is the square ...