The use of square brackets in Lisp and Scheme is much older. IIRC there were Scheme books which used them much earlier.
Interlisp also for example uses square brackets. The left square bracket is equivalent to a round bracket and the right square bracket closes all open levels of brackets.
Interlisp also for example uses square brackets. The left square bracket is equivalent to a round bracket and the right square bracket closes all open levels of brackets.