It seems that matrix input in Stack ignores forbidden words. Is that a bug or a feature or did I something wrong?
I'd expect the input being invalid due to presence of a.
STACK version 2018080600
Sorry about that Martin,
I've checked on my "dev" version and your question does respect the "forbidden words" for matrix and "var matrix" input types. So, this bug was fixed at some point.
Thanks for reporting it, I do appreciate knowing about problems so I can fix them.
Chris