In Tcl there is actually no distinction between commands (often known as 'functions' in other languages) and "syntax". There are no reserved words (like if and while) as exist in C, Java, Python, Perl, etc...
When the Tcl interpreter starts up there is a list of known commands that the interpreter uses to parse a line. These commands include while, for, set, puts, and so on.
They are, however, still just regular Tcl commands that obey the same syntax rules as all Tcl commands, both built-in, and...
