On April 30,2008 HP announced that they had discovered the memristor, a new circuit element introducing the first correct model of ReRAM, and on July 8 they announced they would begin prototyping ReRAM using their memristors.
They had discovered the memristor. This was what HP announced on April 30,2008. The memristor was a new circuit element. This new circuit element was introducing the first correct model of ReRAM. They would begin prototyping ReRAM using their memristors. This was what they announced on July 8.