It's much older. Here is a (legendary) paper on Lisp using Scheme with square brackets from 1983. https://dl.acm.org/doi/pdf/10.1145/800017.800513 https://dl.a

It's much older. Here is a (legendary) paper on Lisp using Scheme with square brackets from 1983. https://dl.acm.org/doi/pdf/10.1145/800017.800513 https://dl.acm.org/doi/pdf/10.1145/800017.800513 Interlisp used it in the 70 already.