Review Questions: 23. On what branch of mathematics is axiomatic semantics based? 24. On what branch of mathematics is denotational semantics based? 25. What is the problem with using a software pure interpreter for operational semantics? Problem set questions: 3. Rewrite the BNF of Example 3.4 to give + precedence over * and force + to be right associative. 7. Using the grammar in Example 3.4, show a parse tree and a leftmost derivation for each of the following statements: 1. A = (A + B)*C 2. A = B + C +A 3. A = A * (B+C) 4. A = B* (C* (A + B)) 11. Consider the following grammar: - a b - bb - a | a Which of the following sentences are in the language generated by this grammar? 1. baab 2. bbbab 3. bbaaaaas EXAMPLE 3.4 An Unambiguous Grammar for Expressions = ABC + | - * | > ( ) |