SYNOPSIS
	closure symbol_function(string arg)
	closure symbol_function(string arg, object ob)

DESCRIPTION
	Constructs a lfun closure, efun closure or operator closure
	from the first arg (string or symbol). For lfuns, the second
	arg is the object that the lfun belongs to. (Ob can also be
	specified as file_name of the object).

EXAMPLES
	symbol_function("efun::users")		-> #'users
	symbol_function("QueryProp", other_obj)	-> other_obj->QueryProp()

SEE ALSO
	lambda(E), quote(E)