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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

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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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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