*4.29: mis.*

**adda/syntax/**typed enclosures:. adda currently reserves the square brackets

as a way to allow more freedom in identifier spellings:

. the space and all printable characters are allowed

as long as every use of square brackets is paired,

because then the ending bracket is well-defined;

eg, [*thi{ i$ ()ne [eg@l iden]ifier] .

. one way to allow multiple uses for square brackets

is to reserve typed brackets: eg,

[this is a single symbol] --. no typing syntax .

[.M(2,3): ...] --. this is typed as being a 2x3 matrix .

{.R: [a,b)} -- a <= x < b for x in reals .

**mis:**

. this seems too arbitrary, with no compelling use cases ...

**sci:**

. however, look at the angle brackets:

while the type is .< ... >

the other use is as a value:

<. ... > or <.type: ...>

and of course the 3rd use is as the less-than,

without any dots nearby .