6. What is the weakest precondition for the following assignment statement: x = 2 * ( y - x) + x { x > 10}

		y > 10
		x > 10
		2y - x > 10
		y - x > 5

7.

The start symbol in a grammar is:

		Terminal symbol
		Nonterminal symbol
		Neither terminal nor nonterminal
		Both terminal and nonterminal

8.

What did Chomsky propose?

		BNF
		Context-free grammars only
		EBNF
		Four classes of grammars, including context-free grammars

10. Which of the following are nonterminal symbols in the grammar rule:

--> + | - |

		+
		-