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13 Aug 2009: S aSa. S bSb. Sε. generates the language of palindromes over the alphabet Σ = {a, b}. ... Examples here are 'swim', 'walk', 'cat' and 'dog'. Notice that there is a grammar that generates the language of palindromes over Σ = {a, b} even though this

18 Oct 2009: 8. Find the minimal polynomials over Q of the complex numbers 53, i+. ... Deduce that the only elements of K(X) which are algebraic over K areconstants.

13 Aug 2009: 3.0.1 Exercises. Provide a context-free grammar for regular expressions over the alphabet {a, b}.

8 Oct 2009: PART II REPRESENTATION THEORYSHEET 4. Unless otherwise stated, all vector spaces are finite-dimensional over C. ...  : a,b,x Fp. of 3 3 upper unitriangular matrices over the finite field Fp of p elements (p prime).Show that G has p

13 Aug 2009: Let us try some examples. Let L be the set of strings over the alphabet {a, b} which have the same number of as as bs. ... Let L be the set of strings over the alphabet {a, b} which have an even number of as and an even number of bs.

13 Aug 2009: The thought-experiment swiftly persuades us that the set of palindromes over an alphabet Σ is not regular (unless Σ contains only one character of course!). ... Let L be the language of palindromes over {a, b}. It isn't regular, but there is no obvious

30 Oct 2009: 5. Let A and B be n n matrices over a field F. ... 13. Let C be an n n matrix over C, and write C = A iB, where A and B are real n n matrices.

13 Aug 2009: The language {aa, ab, ba, bb} is the language of two-letter words over Σ. ... for characters in alphabets;. We tend to use lower-case letters from near the end of the alphabet - like 'u', 'v' and 'w'- for variables to range over strings;.

9 Oct 2009: In whichof these cases is U a vector space over R?(a) x1 > 0.(b) either x1 = 0 or x2 = 0.(c) x1 x2 = 0.(d) x1 x2 = 1.(e) x1 ... 2. Determine which of the following sets of sequences of real numbers (xn) form vector spaces over R.(a) xn is bounded.(b) xn

19 Feb 2009: a) When the culture has been going for just over n minutes, what is the probabilitythat no white cells have yet appeared? ... b) What is the probability that the entire culture eventually dies out?