Many of the warnings produced by the mathematical expression part are quite technical, and could do better to tell the student where they've gone wrong.
Messages should describe the problem in a way the student understands, and ideally offer a suggestion for how to fix it.
Here are some of the obscure messages I've seen:
"No definition of 'dot' of correct type found" when a free variable is generated as a number instead of a vector.
"exprTree is null" when the correct answer is empty (#802)
"no definition of * or listval found" when using square brackets for grouping (#659)
Many of the warnings produced by the mathematical expression part are quite technical, and could do better to tell the student where they've gone wrong.
Messages should describe the problem in a way the student understands, and ideally offer a suggestion for how to fix it.
Here are some of the obscure messages I've seen:
*orlistvalfound" when using square brackets for grouping (#659)