Scheme’s Syntax
Scheme uses one fundamental syntactic construct, the “symbolic expression” or S-expression.
Any “atom” such as a number or a symbol, is an S-expression.
Any parenthesized list of S-expressions, separated by whitespace, is an S-expression.
A procedural form is a list of the form
(procedure-name arg1 arg2 ... argN)
This is sometimes called parenthesized prefix form.