The Peano-Baker series is used to write the STM for general time-dependent systems with this property. Because centers are periodic but not isolated trajectories, limit cycles do not exist in systems with this property. This is the first of two properties that name a (-5[1])class of systems whose output can be obtained (-5[1])by convolving the input with the (15[1])impulse response; those systems have this property and (*) time-invariance. Thevenin and Nortons’ theorems apply (15[1])to (-5[1])circuits with this property, (10[4]-5[1])which circuit (10[1])elements (10[1])like diodes and transistors (10[1])lack. (-5[1])Functions with this property satisfy additivity (10[1])and homogeneity, (10[3]-5[1])or (10[2])the principle of superposition. (10[1])A current-voltage plot for an Ohmic circuit (10[1])element will have this property. For 10 (10[1])points, give (10[2])this property that (-5[1])describes functions (10[1])of the form y (10[1])equals mx (10[2])plus (10[2])b. ■END■ (10[5])