The schemes realizing logical functions are called as logical elements. The basic logical elements have, as a rule, one exit (Y) and some entrances which number is equal to number of arguments (X1; X2; X. XN). On electric circuits logical elements are designated in the form of rectangles with conclusions for entrance ( and days off ( variables. In a rectangle the symbol specifying a functional purpose of an element is represented.
At the pressed button the entrance of elements via the R1 resistor is connected to a source with tension 5B. Thus U1 tension that corresponds to giving on a conclusion of a chip of logical unit will act on an entrance of elements. At the wrung-out button the entrance of an element will be connected to the tire which is under the capacity of the earth that corresponds to giving on a conclusion of a chip logical zero U