In #402 (review) , @eemeli asked:

"For an alternative approach, could we consider changing the let keyword to be set, and for references to declarations to be changed to definitions or assignments? This might make it easier to consider them as assignments rather than initializations."

This would be a non-trivial change, so I wanted to open a separate issue to discuss it. The discussion in #310 overlaps with this issue, but for clarity I wanted to make a separate issue to discuss the specific question about whether the let construct is meant to be a definition construct or an assignment construct.