Codezila

Theory of Automata

Assignment #2

Part #2

Regular Expression # 6

The set of strings over {a,b} that contain at least two a's or exactly two b's.

(a+b)*(a)(b*)a(a+b)*+a*b(a*)b(a*)

Regular Expression # 7

The set of strings over {a,b} that contain even length but not multiple of 3

(aa*)(aaa^)

Regular Expression # 8

The language over {a,b}contains exactly one double letter.

(ε + b)(ab) ∗aa(ba) ∗(ε + b) + (ε + a)(ba) ∗ bb(ab) ∗(ε + a)

Comments

TA ASSIGNMENT 1 PART 3

Theory of Automata Assignment #1 Part #3 Recursive Definition #11: Language of Expressions having at least one operator defined on Σ ={+,-,*,/,a,b} Step 1#- a+b ,a*b,a/b and a-b are in L Step 2#- If x is in L then x+x,x-x,x*x,x/x is also in L Step 3#- No words except generated above can be considered as member of Language. Recursive Definition #12: Language of string starting and ending on different alphabet defined on Σ ={a,b} Step 1#- ab and ba are in L Step 2#- If x is in L then axb,and bxa are also in Σ*. Step 3#- No words except generated above can be considered as member of Language. Recursive Definition #13: Language of even numbers Step 1#- 0 and 2 are in L Step 2#- If x is in L then x+2 and x-2 is also in L . Step 3#- No words except generated above can be considered as member of Language. Recursive Definition #14: Language of negative integers d...

TA ASSIGNMENT 1 Part 2

Theory of Automata Assignment #1 Part #2 Recursive Definition #6: Language of whole numbers Step 1#- 0 and 1 are whole numbers Step 2#- If x is in L then x+1 is also in L Step 3#- No words except generated above can be considered as member of Language. Recursive Definition #7: Language of string having two a's defined on Σ ={a,b} Step 1#- aa and aab are in L Step 2#- If x is in Σ* then axa, aax and xaa are also in Σ* Step 3#- No words except generated above can be considered as member of Language. Recursive Definition #8: Language of string having at least one member defined on Σ ={a,b} Step 1#- a and b are in L Step 2#- If x is in Σ* then ax and bx are also in Σ*. Step 3#- No words except generated above can be c...