1. An electronic multiple-valued register comprising: a first inverted amplifier having an input and an output; a second inverted amplifier having an input and an output; and a first electronic element having a first terminal side connected to said output of said first inverted amplifier and a second terminal side connected to said input of said second inverted amplifier and a second electronic element having a first terminal side connected to said output of said second inverted amplifier and a second terminal side connected to said input of said first inverted amplifier, said first and second electronic elements each having a substantially stair-shaped voltage-current characteristic so as to provide more than two stable levels.