We give an explicit pseudorandom generator (PRG) for read-once AC^ 0, ie, constant-depth
read-once formulas over the basis {wedge, vee, neg} with unbounded fan-in. The seed
length of our PRG is O~(log (n/epsilon)). Previously, PRGs with near-optimal seed length
were known only for the depth-2 case [Gopalan et al., 2012]. For a constant depth d> 2, the
best prior PRG is a recent construction by Forbes and Kelley with seed length O~(log^ 2 n+
log n log (1/epsilon)) for the more general model of constant-width read-once branching …