Returns the third element of a list
Returns the second element of a list
Returns the first element of a list
Returns a list containing all but the first element of the specified list
Converts an integer representing an ASCII character code into a single-character string
Associates application-managed data with a dialog box tile
Closes an open file
Executes an AutoCAD command
Serves as the primary conditional function for AutoLISP
Adds an element to the beginning of a list, or constructs a dotted list
Returns the cosine of an angle expressed in radians
Converts a value from one unit of measurement to another