---

6.7 Expressions

expr	::=	value-path
	|	constant
	|	( expr )
	|	begin expr end
	|	( expr :  typexpr )
	|	expr ,  expr  { , expr }
	|	ncconstr  expr
	|	`tag-name  expr
	|	expr ::  expr
	|	[ expr  { ; expr } ]