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Through this section, we've seen some of the common patterns that can arise in the formulas.Following upon the idea of Design Patterns as describing common programming idioms,``Specification Patterns'' describe common logic specification idioms.For a list of LTL specification patterns, see Property Pattern Mappings for LTL .

In addition, there are also algebraic equivalences for LTL,just as there are for propositional logic . We have already seen a DeMorgan-like example; there are also less obvious equivalences, such as distributing over : ( ) ( ) and the redundancy of -over- : ( ) ( ) It can be fun to dabble in rewriting LTL formulas, but (alas) we won't visit that topic further here.

Using temporal logic in spin

So, we have a Promela program and an LTL formula to verify. How do we use the tool? In SPIN, in the "Run" menu,select "LTL Property Manager". This opens a new window. The top half contains several subpartsfor entering an LTL formula, while the bottom half is for using it.

In the "Formula" textbox, you can type an LTL formula. If you prefer, you can enter the operators using the buttons below,rather than typing. Also, you can use the "Load" button to restore a previously-saved LTLformula from a file. For a formula, the next checkboxes allow you to either verify thatthe formula always holds or never holds. The "Notes" textbox is simply descriptive text. If you plan on savingthe formula, it is helpful to remind yourself what this formula means and is used for.The "Symbol Definitions" textbox is where the LTL variables (typically p , q , etc. ) are related to the Promela code.This is done through #define s which are temporarily added to your Promela code.

Let's consider another critical section example. The following code simply puts the critical section into a loop. Also included isour standard code to check that the mutual exclusion property is satisfied, although the assertion is commented out. 1 /* Number of copies of the process to run. */ 2 #define NUM_PROCS 33 4 show bool locked = false;5 show int num_crit = 0; 67 active[NUM_PROCS] proctype loop()8 { 9 do10 :: true ->11 12 atomic {13 !locked ->14 locked = true; 15 }16 17 /* Critical section of code. */18 /* Something interesting would go here. */ 1920 num_crit++; 21 /* assert(num_crit == 1); */22 num_crit--; 2324 locked = false; 25 /* End critical section of code. */26 od; 27 }

Using temporal logic, we can accomplish the same check without the assertion.There are several similar ways of doing this.

One way is to verify that num_crit always has the value 0 or 1. To do this, we'll make the following definitionin xspin's ``Symbol Definitions'' textbox: #define p ((num_crit == 0) || (num_crit == 1)) We then want to verify that p always holds, so our formula is []p and mark that we always want this formula to hold.

Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Model checking concurrent programs. OpenStax CNX. Oct 27, 2005 Download for free at http://cnx.org/content/col10294/1.3
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