Excel already uses brackets [ ] for the workbook name in a linked cell and
braces { } indicate an array.

I think using these for as subs for ( ) would make things more confusing.

"Serendipian" wrote:

Traditionally, when writing math expressions with nested parenthesis it is
often traditional to express the nesting by judiciously replacing paired
parenthesis with paired brackets and/or braces for clarity, e.g. {... [...
(... )... ]... }. As a suggestion, Excel should be able to detect nested
expressions and replace it with this more legible scheme as an aid to error
detection.