The `abstract` keyword.

Property definitions

	# The `abstract` keyword.
	var n_kwabstract: TKwabstract is writable, noinit

src/parser/parser_nodes.nit:1307,2--1308,50

	redef fun n_kwabstract=(node)
	do
		_n_kwabstract = node
		node.parent = self
	end

src/parser/parser_prod.nit:617,2--621,4