mechanism primitive
parse and create symbol tables	syntax used in .dsl files	comments
begin scope	$<xxx>__BeginScope
output	$<xxx>__Output
set field	$<xxx>__SetField_<yyy>_from_<yyy>	at first, I thought that ‘field’ might be different from Stack, hence, the <yyy>_from_<yyy> syntax now, make ‘field’ the same as the source stack <yyy>_from_<yyy>> is now redundant, this can be replaced by <yyy> (where ‘from’ is no longer needed in the syntax)
append	$<xxx>__AppendFrom_<yyy>
coerce	$<xxx>__CoerceFrom_<yyy>
use symbol tables	(all of the above, plus ...)
begin scope using lookup	$<xxx>__BeginScopeFrom_<yyy>
end scope	$<xxx>__EndScope
begin mapping	$<xxx>__BeginMapping	map means iteration over list
next	$<xxx>__Next
end mapping	$<xxx>__EndMapping
external methods
	$name__GetName
	$name__Combine
	$scriptDeclaration__ClearFormalsInBootstrap
	N.B. “$” is a legal character in an identifier (CL identifier rules)
	N.B. “_” is a legal character in an identifier (CL identifier rules)