Automata and compiler, Theory of Computation

Assignment Help:

Automata and Compiler

(1) [25 marks] Let N be the last two digits of your student number. Design a finite automaton that accepts the language of strings that end with the last four bits of the binary expansion of N. (1.1) Make a regular expression ? of this language. For example the set of strings that end with 101 is expressed by a regular expression (0+1)*101. (1.2) Make an NFA that accepts this expression ?. You should remove any ?-moves that can be done trivially by inspection. (1.3) Make a subset automaton that accepts the language. (1.4) Perform state minimization on the above automaton.

(2) [25 marks] A CFG is given by S ? aSbS, S ? bSaS, S ? c

(2.1) Draw a syntax chart for this grammar. [5]

(2.2) Write a Python program for the recursive descent parser Trace the parser using two strings of at least 10 symbols, one for an accepted case and one for an unaccepted case. Do the trace using the style in the notes. [20]

(3) [25 marks] A sample program for computing the greatest common divisor by recursive call and its object program are given below. Some sample comments are given.

const a=75, b=55;

var x, y;

procedure gcd;

var w;

begin

if y>0 then begin

w:=y;

y:=x ? (x/y)*y;

x:=w;

call gcd;

end;

end;

begin

x:=a; y:=b;

call gcd;

write(x);

end.

0 jmp 0 21 Jump to 21, start of main

1 jmp 0 2

2 inc 0 4

3 lod 1 4

4 lit 0 0 Load literal 0

5 opr 0 12 Test if y>0

6 jpc 0 20 Jump to 20 if false

7 lod 1 4 Load y

8 sto 0 3 Store in w

9 lod 1 3

10 lod 1 3

11 lod 1 4

12 opr 0 5

13 lod 1 4

14 opr 0 4

15 opr 0 3

16 sto 1 4

17 lod 0 3

18 sto 1 3

19 cal 1 2

20 opr 0 0

21 inc 0 5

22 lit 0 75

23 sto 0 3

24 lit 0 55

25 sto 0 4

26 cal 0 2

27 lod 0 3

28 wrt 0 0 Write stack top

29 opr 0 0


Related Discussions:- Automata and compiler

Local and recognizable languages, We developed the idea of FSA by generaliz...

We developed the idea of FSA by generalizing LTk transition graphs. Not surprisingly, then, every LTk transition graph is also the transition graph of a FSA (in fact a DFA)-the one

Myhill-nerode theorem, The Myhill-Nerode Theorem provided us with an algori...

The Myhill-Nerode Theorem provided us with an algorithm for minimizing DFAs. Moreover, the DFA the algorithm produces is unique up to isomorphism: every minimal DFA that recognizes

Turing machine, design a turing machine that accepts the language which con...

design a turing machine that accepts the language which consists of even number of zero''s and even number of one''s?

Myhill graphs, Another way of representing a strictly 2-local automaton is ...

Another way of representing a strictly 2-local automaton is with a Myhill graph. These are directed graphs in which the vertices are labeled with symbols from the input alphabet of

Gastric juice, what are composition and its function of gastric juice

what are composition and its function of gastric juice

Formal language theory, This was one of the ?rst substantial theorems of Fo...

This was one of the ?rst substantial theorems of Formal Language Theory. It's maybe not too surprising to us, as we have already seen a similar equivalence between LTO and SF. But

Path function of a nfa, The path function δ : Q × Σ*→ P(Q) is the extension...

The path function δ : Q × Σ*→ P(Q) is the extension of δ to strings: Again, this just says that to ?nd the set of states reachable by a path labeled w from a state q in an

Union, Intuitively, closure of SL 2 under intersection is reasonably easy ...

Intuitively, closure of SL 2 under intersection is reasonably easy to see, particularly if one considers the Myhill graphs of the automata. Any path through both graphs will be a

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd