 5.5.1: Show that EQCFG is undecidable.
 5.5.2: Show that EQCFG is coTuringrecognizable.
 5.5.3: Find a match in the following instance of the Post Correspondence P...
 5.5.4: If A m B and B is a regular language, does that imply that A is a r...
 5.5.5: Show that ATM is not mapping reducible to ETM. In other words, show...
 5.5.6: Show that m is a transitive relation.
 5.5.7: Show that if A is Turingrecognizable and A m A, then A is decidable.
 5.5.8: In the proof of Theorem 5.15, we modied the Turing machine M so tha...
 5.5.9: Let T = {hMi M is a TM that accepts wR whenever it accepts w}. Sho...
 5.5.10: Consider the problem of determining whether a twotape Turing machi...
 5.5.11: Consider the problem of determining whether a twotape Turing machi...
 5.5.12: Consider the problem of determining whether a singletape Turing ma...
 5.5.13: A useless state in a Turing machine is one that is never entered on...
 5.5.14: Consider the problem of determining whether a Turing machine M on a...
 5.5.15: Consider the problem of determining whether a Turing machine M on a...
 5.5.16: Let = {0,1, } be the tape alphabet for all TMs in this problem. Den...
 5.5.17: Show that the Post Correspondence decidable over the unary alphabet...
 5.5.18: Show that the Post Correspondence undecidable over the binary alpha...
 5.5.19: In the silly Post Correspondence Problem, SPCP, the top string in e...
 5.5.20: Prove that there exists an undecidable subset of {1}.
 5.5.21: Let AMBIGCFG = {hGi G is an ambiguous CFG}. Show that AMBIGCFG is ...
 5.5.22: Show that A is Turingrecognizable iff A m ATM.
 5.5.23: Show that A is decidable iff A m 01.
 5.5.24: Let J = {w either w = 0x for some x ATM, or w = 1y for some y ATM ...
 5.5.25: Give an example of an undecidable language B, where B m B.
 5.5.26: Dene a twoheaded nite automaton (2DFA) to be a deterministic nite ...
 5.5.27: A twodimensional nite automaton (2DIMDFA) is dened as follows. Th...
 5.5.28: Rices theorem. Let P be any nontrivial property of the language of ...
 5.5.29: Show that both conditions in 5.28 are necessary for proving that P ...
 5.5.30: Use Rices theorem, which appears in 5.28, to prove the undecidabili...
 5.5.31: Letf(x) =(3x + 1 for odd x x/2 for even x for any natural number x....
 5.5.32: Prove that the following two languages are undecidable. a. OVERLAPC...
 5.5.33: Consider the problem of determining whether a PDA accepts some stri...
 5.5.34: Let X = {hM,wi M is a singletape TM that never modies the portion...
 5.5.35: Say that a variable A in CFG G is necessary if it appears in every ...
 5.5.36: Say that a CFG is minimal if none of its rules can be removed witho...
Solutions for Chapter 5: R E D U C I B I L I T Y
Full solutions for Introduction to the Theory of Computation  3rd Edition
ISBN: 9781133187790
Solutions for Chapter 5: R E D U C I B I L I T Y
Get Full SolutionsIntroduction to the Theory of Computation was written by and is associated to the ISBN: 9781133187790. This textbook survival guide was created for the textbook: Introduction to the Theory of Computation, edition: 3. Since 36 problems in chapter 5: R E D U C I B I L I T Y have been answered, more than 16355 students have viewed full stepbystep solutions from this chapter. This expansive textbook survival guide covers the following chapters and their solutions. Chapter 5: R E D U C I B I L I T Y includes 36 full stepbystep solutions.

Astronomy
The scientific study of the universe; it includes the observation and interpretation of celestial bodies and phenomena.

Black hole
A massive star that has collapsed to such a small volume that its gravity prevents the escape of all radiation.

Desert pavement
A layer of coarse pebbles and gravel created when wind removed the finer material.

Dipslip fault
A fault in which the movement is parallel to the dip of the fault.

Divide
An imaginary line that separates the drainage of two streams; often found along a ridge.

Dome
A roughly circular upfolded structure similar to an anticline.

Drawdown
The difference in height between the bottom of a cone of depression and the original height of the water table.

Eclipse
The cuttingoff of the light of one celestial body by another passing in front of it.

Euphotic zone
The portion of the photic zone near the surface where light is bright enough for photosynthesis to occur.

Irregular galaxy
A galaxy that lacks symmetry.

Leaching
The depletion of soluble materials from the upper soil by downwardpercolating water.

Lightyear
The distance light travels in a year; about 6 trillion miles.

Local group
The cluster of 20 or so galaxies to which our galaxy belongs.

Lunar highlands
See Terrae.

Normal fault
A fault in which the rock above the fault plane has moved down relative to the rock below.

Open system
One in which both matter and energy flow into and out of the system. Most natural systems are of this type.

Seawall
A barrier constructed to prevent waves from reaching the area behind the wall. Its purpose is to defend property from the force of breaking waves.

Solar winds
Subatomic particles ejected at high speed from the solar corona.

Subpolar low
Low pressure located at about the latitudes of the Arctic and Antarctic circles. In the Northern Hemisphere the low takes the form of individual oceanic cells; in the Southern Hemisphere there is a deep and continuous trough of low pressure.

Trophic level
A nourishment level in a food chain. Plant and algae producers constitute the lowest level, followed by herbivores and a series of carnivores at progressively higher levels.