Edition- Complete Solutions Manual
(Step-by-Step Answers for All Chapters)
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What is recommended for students who find the book easy?
They should read through it quickly and then explore more advanced texts.
What should be introduced only when students feel their thoughts exceed their ability to
express them?
Advanced mathematical notation.
What mistake should not be made regarding mathematical rigor?
Believing that a subject becomes more rigorous due to the use of symbols.
What is the significance of the language PALINDROME in the course?
It must become a member of the immediate family of languages studied.
What concept should be introduced with Theorem 1?
The concept of proof.
What is the Fibonacci sequence in relation to word lengths?
The number of words of length n is the sum of the number of words of length (n-1) and (n-2).
What is the smallest word not in the language S*?
The smallest word not in this language is 'a'.
What is the condition for a string to be a palindrome?
A string is a palindrome if it reads the same forwards and backwards.
How many palindromes of length 3 are there?
There are four palindromes of length 3: aaa, aba, bab, bbb.
What happens when you delete an equal number of letters from both ends of a
palindrome?
It leaves a palindrome.
What is the relationship between S and T if S is a proper subset of T?
S is smaller than T, denoted as S ⊂ T.
What is the significance of the string 'abbba' in the context of the language?
The string 'abbba' is not in the language.
What is the result of concatenating two palindromes?
The result is also a palindrome.
What is the algorithm to determine if a string is a palindrome?
If the length of the string is less than 2, it is a palindrome; otherwise, compare the first and last
letters and repeat.
How many arrangements are there for 3 (xxx) and 5 (xx)?
There are 56 arrangements (eight choose three).
What is the closure property of S*?
Any word in S* is also in T.
What is the main goal of the Computer Theory course?
To provide an intellectual enrichment rather than vocational skills.
,Why are students often suspicious of Computer Theory courses?
They fear being required to take extra theoretical math courses.
What is emphasized about the Computer Theory course?
It is not primarily a mathematics course but focuses on mathematical models.
What is the classical format of the text?
Theorem-proof-theorem-proof model.
What issue do many students face regarding proofs?
They are functionally mathematically illiterate and fear constructing proofs
What is the relationship between the lengths of words in S*?
There can be no more six-letter words than twelve-letter words in S*.
What is the set of all strings of a's and b's?
S and T both represent the set of all strings of a's and b's.
What is the condition for a word to be in S*?
No words in S* contain an odd number of b's.
What is the implication of the algorithm for finding z?
If length(x) = length(y), then they form a palindrome of even length.
What is the result of applying the algorithm to a palindrome string?
It reduces the palindrome to a central core of one or two letters.
What is the significance of the term 'recursive programming'?
It is helpful for understanding recursive definitions.
What is the relationship between the number of palindromes of length 2 and length 1?
There are as many palindromes of length 2 as there are of length 1.
What is the implication of the theorem regarding (S)?
(S) = S*.
What does the term 'closure' refer to in the context of languages?
It refers to the property that any concatenation of words in a language remains within that
language.
What is the result of the concatenation of two different palindromes?
It can create a new palindrome or a non-palindrome depending on their structure.
What is a recursive definition?
A definition that defines a function or set in terms of itself.
What are the two rules for defining the set of even numbers?
Rule 1: 2, 4, 6, 8, and 10 are in EVEN. Rule 2: If x is in EVEN, then so is x + 10.
What is the purpose of mathematical induction?
To verify the truth of a result without understanding why the claim is true.
What is the rule for defining polynomials?
Rule 1: Any number is in POLYNOMIAL. Rule 2: The variables x and y are in POLYNOMIAL.
Rule 3: If a and b are in POLYNOMIAL, then so are a+b, a-b, (a), and ab.
How can we produce an odd number from the definition of even numbers?
By adding an even number to some arbitrary integer n, the resulting sum has the same parity as
n.
What are the rules for defining the set of digits?
Rule 1: 1, 2, 3, 4, 5, 6, 7, 8, and 9 are in DIGITS. Rule 2: If x and y are in DIGITS, then so are
x0 and xy.
What is the recursive definition of powers of two?
Rule 1: 1 is in POWERS-OF-TWO. Rule 2: If x is in POWERS-OF-TWO, so is 2 * x.
, What is the rule for defining even strings?
Rule 1: A is in EVENSTRING. Rule 2: If w is in EVENSTRING, so are waa, wab, wba, and
wbb.
What is the rule for defining odd strings?
Rule 1: a and b are in ODDSTRING. Rule 2: If w is in ODDSTRING, so are waa, wab, wba, and
wbb.
What is the definition of a palindrome?
Rule 1: a, b, and A are in PALINDROME. Rule 2: If x is in PALINDROME, then so are xx, axa,
and bxb.
What are the forbidden substrings of length 2?
++, -+, "4, /+, (+, (i, -;, c, +/, -/, L, i, (/.
What are the forbidden substrings of length 3?
Any combination that does not contain shorter forbidden substrings.
How many ways can we prove that 14 is even?
There are eleven ways to prove that 14 is even.
What is the result of 2 + 2?
4
What is the result of 4 + 2?
6
What is the result of 4 + 4?
8
What is the result of 6 + 2?
8
What is the result of 6 + 4?
10
What is the result of 6 + 6?
12
What is the result of 8 + 2?
10
What is the result of 8 + 4?
12
What is the result of 10 + 2?
12
What is the result of 10 + 4?
14
What is the result of 12 + 2?
14
What are the 8 arrangements of the digits 1, 2, 3, 4 that can be obtained?
1234, 4321, 2341, 3214, 1432, 3412, 4123, 2143
What alphabet is used throughout the text instead of {0,1}?
{a,b}
What does r* really mean?
(r)*
What is the language associated with (r, + r,)r,?
All words made up of an initial factor from the language associated with either r1 or r2 and a
second factor from the language associated with r3.