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

Describe about micro-controllers, Q. Describe about Micro-controllers? ...

Q. Describe about Micro-controllers? Micro-controllers: These are a specialized device controlling computer which comprises every function of computers on a single chip. Chip

What is zero address instruction, Zero address instruction.  It is also...

Zero address instruction.  It is also possible to use instruction where the location s of all operand is explained implicitly. This operand of the use of the method for storing

How is network examined by intranets, How is network examined by intranets,...

How is network examined by intranets, extranets and Internet? When more and more businesses seek to build their mission critical business solutions onto IP networks, networking

What is common control switching system, What is common control switching s...

What is common control switching system? Explain. Common Control Switching System: It is a functional block diagram of a common control switching system is demonstrated in figu

What is external modems, Q. What is External Modems? External Modems: M...

Q. What is External Modems? External Modems: Modems externally associated to PC via a parallel or serial port and into a telephone line at the other end.  They can generally co

What is the prominence of rs232-c in serial communication, What is the prom...

What is the prominence of RS232-C in serial communication?  Name some application where you see its use.  RS-232 stands for Recommend Standard number 232 and C is the latest re

Factor causing parallel overheads, Performance metrics aren't able to attai...

Performance metrics aren't able to attain a linear curve in comparison to increase in number of processors in parallel computer. The main reason for above situation is presence of

What is static timing, What is Static timing a. Delays over all paths a...

What is Static timing a. Delays over all paths are added up. b. All possibilities, including false paths, verified without the need for test vectors. c. Faster than simul

QUELING SYTEM , SHOW THAT AVERAGE NUMBER OF UNIT IN A (M/M/1) QUELING SYTEM...

SHOW THAT AVERAGE NUMBER OF UNIT IN A (M/M/1) QUELING SYTEM IS EQUAL TO P/(1-p). NOTE:P=ROW

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