Total quantities, combining both small-signal and large-signal quantities, are denoted using lower case letters and uppercase subscripts. For example, the total input voltage to the aforementioned transistor would be denoted as v I N ( t ) {\displaystyle v_{\mathrm {IN} }(t)} . The small-signal model of the total signal is then the sum of the DC component and the small-signal component of the total signal, or in algebraic notation, v I N ( t ) = V I N + v i n ( t ) {\displaystyle v_{\mathrm {IN} }(t)=V_{\mathrm {IN} }+v_{\mathrm {in} }(t)} .