HELP name
(HELP)

	command.  Prints information from the reference manual about
	the primitive procedure named by the input.  With no input,
	lists all the primitives about which help is available.
	If there is an environment variable LOGOHELP, then its value
	is taken as the directory in which to look for help files,
	instead of the default help directory.

	If HELP is called with the name of a defined procedure for which there
	is no help file, it will print the title line of the procedure
	followed by lines from the procedure body that start with semicolon,
	stopping when a non-semicolon line is seen.

	Exceptionally, the HELP command can be used without its default
	input and without parentheses provided that nothing follows it on
	the instruction line.