On Tue, Apr 7, 2020, 08:14 <whygee at f-cpu.org> wrote: > Have a look : > http://www.ecs.umass.edu/ece/koren/arith/simulator/Add/lookahead/ Neat! It is, however, limited to only 2 levels of lookahead circuits, which is only sufficient for 16 or maybe 32 bits, not for 64 or more. Jacob