Syntax of A++ including pre-defined primitive abstractions

$\displaystyle \flq expression\frq\$	$\displaystyle ::=$	$\displaystyle \flq abstraction\frq\ \vert$	(6)
		$\displaystyle \flq reference\frq\ \vert$
		$\displaystyle \flq synthesis\frq\ \vert$
		$\displaystyle \flq predefined\: abstraction\frq\$
$\displaystyle \flq abstraction\frq\$	$\displaystyle ::=$	$\displaystyle '(' \: define \: \flq variable\frq\ \: \flq expression\frq\ \: ')' \: \vert$	(7)
		$\displaystyle '(lambda (' \: \{ \flq variable \frq\ \} \: ')'$
		$\displaystyle \flq expression\frq\ \: \{ \: \flq expression\frq\ \} \: ')'$
$\displaystyle \flq reference\frq\$	$\displaystyle ::=$	$\displaystyle \flq variable\frq\$	(8)
$\displaystyle \flq synthesis\frq\$	$\displaystyle ::=$	$\displaystyle '(' \: \flq operator \: expression\frq\ \: \{ \flq expression\frq\ \} \: ')'$	(9)
$\displaystyle \flq variable\frq\$	$\displaystyle ::=$	$\displaystyle \flq symbol\frq\$	(10)
$\displaystyle \flq operator \: expression\frq\$	$\displaystyle ::=$	$\displaystyle \flq abstraction\frq\ \: \vert \: \flq reference\frq\ \: \vert \: \flq synthesis\frq\ \vert$	(11)
		$\displaystyle \flq predefined \: operation\frq\$
$\displaystyle \flq predefined\: abstraction\frq\$	$\displaystyle ::=$	$\displaystyle \flq predefined \: value\frq\ \vert$	(12)
		$\displaystyle \flq predefined \: operation\frq\$
$\displaystyle \flq predefined \: value\frq\$	$\displaystyle ::=$	$\displaystyle \flq vmzero\frq\ \vert \flq vmtrue\frq\ \vert \flq vmfalse\frq\ \vert$	(13)
		$\displaystyle \flq double \: quoted \: string\frq\ \vert \flq single \: quoted \: string\frq\$
$\displaystyle \flq double \: quoted \: string\frq\$	$\displaystyle ::=$	$\displaystyle '''' \flq string\frq\ ''''$	(14)
$\displaystyle \flq single \: quoted \: string\frq\$	$\displaystyle ::=$	$\displaystyle ''' \flq string\frq\$	(15)
$\displaystyle \flq predefined \: operation\frq\$	$\displaystyle ::=$	$\displaystyle \flq incr\frq\ \vert \flq print\frq\ \vert \flq load\frq\ \vert \flq equalx\frq\ \vert \flq quit\frq\$	(16)