I find the excellent Scheme manual slightly peculiar because the models given as they define some syntax, (e.g lambda) omit the mandatory parentheses. It is as if the manual ignores the blindingly obvious fact that Scheme is homoiconic. John McCarthy thought that no one would want to write LISP programs with all those parentheses and very early he provided an Algol like syntax for LISP and a program to convert. No one used the Algol syntax. Even before editors learned to match parentheses people found the parentheses form easier to use.