Homework 1: Syntax
Due
February 4


1.  Given the following grammar rules:

unsigned_real  → integer . integer

integer digit | digit  integer

digit 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

 

a) Write a complete leftmost derivation of the sentence (don't skip any steps):   624.93

b)  Construct a complete parse tree for the sentence in part a).

2. Given the expression grammar in Example 2.8, construct complete parse trees for the sentences:

a)    ( A + B ) * C

b)    4 + 6 * 2 * 3 - 9

3. Do parts (a) and (b) of Exercise 2.13 on p. 105.

 

4. Describe in English the language that the following grammar generates:

<S> → <A> <B> <C>

<A> → a <A> | a

<B>→ b <B> | b

<C> → c <C> | c

5. Do Exercise 2.10 on p. 104  (make the necessary modifications to the grammar in Example 2.8).

6. Define BNF grammar rules for a language that consists of binary strings with at least 3 consecutive 1 bits.

Examples:

Several valid strings in this language: 1011100101, 11111, 100101111

Several strings that are NOT valid: 1000110, 11011011, 10000000