Sound and complete, Computer Engineering

Assignment Help:

Dictator Dim wants to replace counting, in particular, counting the population of his land. To keep an accurate population count, Dictator Dim has instructed his secretary to add one + symbol to a record each time a citizen is born, and one - symbol to the record whenever a citizen dies. This has been going on ever since his rule began.

Dictator Dim is not concerned so much with the actual total population of his lands, just with the net change in population since his rule began. He would be forever disgraced if the net population change were ever negative. Refusing to solve this problem by counting, Dictator Dim instructs his secretary to find a sound and complete logic for the subset of all records that would not disgrace him.
More formally, define the following truth concept WFF's = {+; -}, i.e., all strings composed of only plus and minus symbols.
A WFF x is true if every prefix of x contains at least as many + symbols as - symbols.

Find a logic for this truth concept by proving that it is sound and complete. Hint: it may help to define additional judgement form(s)


Related Discussions:- Sound and complete

Decision support at a digital hospital, Heart disease is the number-one kil...

Heart disease is the number-one killer in the United States, and in a cardiac crisis, each minute matters. Indiana Heart Hospital (IHH) is a new cardiac hospital that saves life b

Demostrate the example of spreadsheet, Now consider the following spreadshe...

Now consider the following spreadsheet: Formula in cell D2 is = (B2/C2) Replicating this formula (by highlighting then drag down to D7) gives all the formulas needed in cell

Should validation occur server-side or client-side, Should validation (did ...

Should validation (did the user enter a real date) occur server-side or client-side? Why? Validation will be done in both sides i.e., at the server side and client side. Ser

Including the titles, Your company is planning a party for employees, and y...

Your company is planning a party for employees, and you have been asked to set up a spreadsheet to track the attendees and to measure the associated cost. Every employee is permitt

Demultiplexers, Explain briefly about demultiplexers?

Explain briefly about demultiplexers?

Define entry section and exit section, Define entry section and exit sectio...

Define entry section and exit section. The critical section problem is to design a protocol that the processes can use to cooperate. Every process must request permission to e

What is a spanning tree, What is a spanning Tree? A spanning tree is a ...

What is a spanning Tree? A spanning tree is a tree associated with a network. All the nodes of the graph appear on the tree once. A minimum spanning tree is a spanning tree

Digital communication systems, a pcm has the following parameters a maximum...

a pcm has the following parameters a maximum analog input frequency of 4khz maximum decoded voltage at the receiver of 2.55v minimum dr of 6db compute minimum sampling rate,minimum

When the get cursor command used in interactive lists, When the get cursor ...

When the get cursor command used in interactive lists? If the hidden information is not enough to uniquely recognize the selected line, the command GET CURSOR is used.  The GET

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