US Patent 10534836 Four steps associative full adder

A method to add a first one bit variable with a second one bit variable and a carry-in bit, to generate a sum bit and a carry-out bit, the method includes initiating the sum bit to the value of the second one bit variable, initiating the carry-out bit to a value of the carry-in bit and modifying the sum bit and the carry-out bit if a comparison of a sequence of the first one bit variable, the second one bit variable and an inverse value of the carry-in bit matches one of a predefined set of a change trigger sequences.