daisylab
commented
1 year ago I followed the link you mentioned, and found that it's certainly broken. Sorry for that.
However, I personally think that the links provided in "boolean logic" and "truth tables" will be enough for the badge. I can tell you because I've earned it myself.
Maybe next link will be in help:
https://ibm.ent.box.com/notes/928968934657?s=42l32h0uno2ndq5o9omb7hl17dddpjuk
At https://github.com/IBM/LNN/tree/master/tutorials#prerequisite , there's a link to elementary material https://ibm.box.com/s/c0sq8d7tc01tw1c7xq4k8oedajto84n8 , but box.com reports that it's been removed or that I don't have access to it.