letI for use in do-notation. #
This files implements the
letI' macros which have the same semantics as
letI, but are
doElems and can be used inside do-notation.
They need an apostrophe after their name for disambiguation with the term variants.
This is necessary because the do-notation has a hardcoded list of keywords which can appear both
as term-mode and do-elem syntax (like for example