Small nitpick: it's more like: Mit-Arbeit-er + Erfindungs + Gesetz. There's no -erer suffix, the first -er makes Arbeit + er (= work + er). Second one belongs

Small nitpick: it's more like: Mit-Arbeit-er + Erfindungs + Gesetz. There's no -erer suffix, the first -er makes Arbeit + er (= work + er). Second one belongs to the word Erfindung (= invention)