A device, comprising: an array of cells, wherein the cells are arranged in columns and rows; wherein each cell comprises a memristive device; an interfacing circuit that is coupled to each cell of the array of cells; wherein the interfacing circuit is arranged to: receive or generate first variables and second variables; generate memristive device input signals that once provided to memristive devices of the array will cause a change in a state variable of each of the memristive devices of the cells of the array, wherein the change in the state variable of each of the memristive devices of the cells of array reflects a product of one of the first variables and one of the second variables; provide the memristive device input signals to memristive devices of the array; and receive output signals that are a function of at least products of the first variables and the second variables;
Please help me write a proper abstract based on the patent claims. CLAIM: 1. An analog multiplier, comprising: an input circuit, a memristive device, and an output circuit; wherein the memristive device is coupled between the input circuit and the output circuit; wherein the input circuit is arranged to: receive or generate a first variable and a second variable; generate at least one memristive device input signal that once provided to the memristive device will cause a change in a state variable of the memristive device, wherein the change in the state variable of the memristive device reflects a product first and second variables; provide the memristive device the at least one memristive device input signal; wherein the output circuit is arranged to evaluate the state variable of the memristive device and to generate information about the above product. 2. The analog multiplier according to claim 1, wherein a derivative of the state variable equals an output of a first function applied on the state variable and on the at least one memristive input signal; and an output signal of the memristive device equals a product of the at least one memristive device input signal and an output of a second function applied on the state variable and on the at least one memristive device input signal; wherein the input circuit is arranged to generate the at least one memristive device in response to the first and second functions. 3. The analog multiplier according to claim 1, wherein the memristive device is a memristor. 4. The analog multiplier according to claim 3, wherein the input circuit is arranged to generate a memristive device input signal of a value that represents the first variable and to cause the memristive device to receive the value during a duration that represents the second variable. 5. The analog multiplier according to claim 3, wherein the at least one memristive device input signal is a voltage signal. 6. The analog multiplier according to claim 3, wherein the at least one memristive device input signal is a current signal. 7. The analog multiplier according to claim 3, wherein the input circuit comprises first and second transistors, the first transistor is arranged to provide positive memristive device input signals and the second transistor is arranged to provide negative memristive device input signals. 8. A device, comprising: an array of cells, wherein the cells are arranged in columns and rows; wherein each cell comprises a memristive device; an interfacing circuit that is coupled to each cell of the array of cells; wherein the interfacing circuit is arranged to: receive or generate first variables and second variables; generate memristive device input signals that once provided to memristive devices of the array will cause a change in a state variable of each of the memristive devices of the cells of the array, wherein the change in the state variable of each of the memristive devices of the cells of array reflects a product of one of the first variables and one of the second variables; provide the memristive device input signals to memristive devices of the array; and receive output signals that are a function of at least products of the first variables and the second variables. 9. The device according to claim 8, wherein the memristive device is a memristor. 10. The device according to claim 9, wherein the interfacing circuit is arranged to generate memristive device input signals of values that represents the first variables and to cause the memristive devices to receive the values during durations that represent the second variables. 11. The device according to claim 8, wherein the interfacing circuit is arranged to: provide a same first memristive device input signal to all memristive devices of a single row of the array; send a same second memristive device input signal to all memristive devices of a single column of the array and to read in parallel; and read in parallel a state of memristive devices of a single column of the array. 12. The device according to claim 11, wherein the memristive device is a memristor. 13. The device according to claim 11, wherein the interfacing circuit is arranged to receive, from each column of cells, an aggregate current that is a sum of output currents of memristive devices of cells of the column. 14. The device according to claim 11, wherein the interfacing circuit and the array of cells form an array of synopses. 15. The device according to claim 8, comprising a machine learning controller that is arranged to execute machine learning algorithms that involve feeding to the interfacing circuit the first and second variables. 16. A method for analog multiplication of a first and a second variable, the method comprises: generating of receiving the first variable and the second variable; generating at least one memristive device input signal that once provided to the memristive device will cause a change in a state variable of the memristive device, wherein the change in the state variable of the memristive device reflects a product of first and second variables; providing the memristive device the at least one memristive device input signal to the memristive device; and evaluating the state variable of the memristive device and generating information about the above product. 17. The method according to claim 16, wherein a derivative of the state variable equals an output of a first function applied on the state variable and on the at least one memristive input signal; and an output signal of the memristive device equals a product of the at least one memristive device input signal and an output of a second function applied on the state variable and on the at least one memristive device input signal wherein the method comprises generating the at least one memristive device in response to the first and second functions. 18. The method according to claim 16, wherein the memristive device is a memristor. 19. The method according to claim 18, comprising generating a memristive device input signal of a value that represents the first variable and to cause the memristive device to receive the value during a duration that represents the second variable. 20. The method according to claim 18, wherein the at least one memristive device input signal is a voltage signal. 21. The method according to claim 18, wherein the at least one memristive device input signal is a current signal. 22. The method according to claim 18, comprising providing by a first transistor memristive device input signals and providing by a second transistor negative memristive device input signals. 23. A method, comprising: receiving or generating first variables and second variables; generating memristive device input signals that once provided to memristive devices of an array of cells will cause a change in a state variable of each of the memristive devices of the cells of the array, wherein the change in the state variable of each of the memristive devices of the cells of array reflects a product of one of the first variables and one of the second variables; providing the memristive device input signals to memristive devices of the array; and receiving output signals that are a function of at least products of the first variables and the second variables. 24-30. (canceled)