4.3 Whitespace Location

Zero or more whitespace characters may be placed between symbols in a Stan program. For example, zero or more whitespace characters of any variety may be included before and after a binary operation such as a * b, before a statement-ending semicolon, around parentheses or brackets, before or after commas separating function arguments, etc.

Identifiers and literals may not be separated by whitespace. Thus it is not legal to write the number 10000 as 10 000 or to write the identifier normal_lpdf as normal _ lpdf.