Q.Name the universal gate used to realize OR – AND logic.

Logic circuit realization is the process of drawing the gate circuit that implements a given Boolean expression. Because most expressions are written as a sum of products or a product of sums, they naturally map onto two-level circuits.

An expression in sum-of-products (SOP) form is implemented as AND–OR logic: a first level of AND gates forms each product term and a second level OR gate sums them. For example, $Y = AC + \overline{C}$ is drawn with an AND gate for $AC$, an inverter for $\overline{C}$, and an OR gate combining them. AND–OR logic is the standard way to realize an SOP expression, and the universal gate used to build it directly is the NAND gate, giving the familiar NAND–NAND circuit. …