ref: 6fea339d0e40d598f093146c0d096b64e2e10c91
parent: f00d509c3efd320c795af6964d861a73761da3e9
author: Philip Silva <philip.silva@protonmail.com>
date: Tue Aug 3 06:54:27 EDT 2021
Some code for gradients - upgrade to more recent plan9 go library