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

Illustrate role of world wide web in field of e-commerce, Illustrate the ro...

Illustrate the role of World Wide Web into the field of e-commerce. In the 1990 year, the advent of the World Wide Web upon the Internet represented a turning point into e-com

Serial port communication, The 68HC11F1 has two types of serial ports namel...

The 68HC11F1 has two types of serial ports namely asynchronous (SCI) and synchronous (SPI). The most common form of communication device used in control is the SCI as this provides

What is random access memory, What is Random access memory (RAM) This i...

What is Random access memory (RAM) This is a volatile memory (i.e. contents are lost when computer is switched off). A user can write or delete data and read the contents. Befo

ANS, Smugglers are becoming very smart day by day. Now they have developed ...

Smugglers are becoming very smart day by day. Now they have developed a new technique of sending their messages from one smuggler to another. In their new technology, they are send

Subtraction of 01000-01001 using 2's complement method, Subtraction of 0100...

Subtraction of 01000-01001 using 2's complement method. Ans. Firstly 1's complement of 01001 is 10110 and 2's complement is 10110+ 1 =10111. Thus   01000 =  01000 - 01001

Define assembly, Define Assembly Assembly is a one deployable unit that...

Define Assembly Assembly is a one deployable unit that contains information about the execution of classes, structures and interfaces. it also keeps the information about itsel

Explain the relationship between translated & linked address, Explain the r...

Explain the relationship amongst Translated address and Linked address. Translated address: Address assigned through the translator Linked address: Address assigned

How can i make text in a cell display in multiple lines, When entering word...

When entering word into the cell, press Alt-Enter to insert a line break. When you do so, Excel will automatically give text wrapping to the cell. To reformat existing cells s

Analog to Digital convertor, The A/D converter whose conversion time is ind...

The A/D converter whose conversion time is independent of the number of bits is ? Ans. Parallel conversion is the A/D converter whose conversion time is independent of the Numbe

Operating system, what is batch system?how the disadvantage of batch system...

what is batch system?how the disadvantage of batch system are overcome in multi-programming operating system?also describe how multi-programmed operating system is milestone in dev

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