the district court erred as a matter of law by construing the acetate buffer limitation to encompass subject matter that the applicants disparaged and relinquished throughout the specification and during prosecution that the word separately added by right or something akin to that even they did not do that they did not do that and if you read the claim language acetate buffered in a vacuum you could take a broad enough  cover that but when you read it in the context of this specification and the way it's used it's clear that they're talking about an added acetate buffer or a separate acetate buffer not the acetate coming described in the specification or the prosecution history as a mixed buffer as an acetate and tartrate buffer there is not a single statement in the pattern specification or in the look at the prosecution history j three eight six you have the interview summary where the examiner says they showed unexpected results that acetate is a member of the genus and tartrate with the stabilize so what was the examiner comparing the examiner tells us in the reasons for allowance j thirty eight eighty nine the specification shows that tartrate buffer unexpectedly destabilizes the claim peptides well acetate has an unforeseen stabilizing effect so he's comparing the partridge examples in the specification to the acetate examples the added buffer added acetate versus added tartrate and he says you show an unexpected results for one over the other it can't be that you so it's and hants enhanced compared to what if you read two sentences later prior formulations employing a perpetrate buffer contain pharmaceutically significant amounts of unwanted degradation products so we have to have prosecution history where the examiner allowed the claim based on a comparison of the tartrate and the acetate example if you look at it spans column two and in the column three at line sixty six through sixty eight of column two the pattens talking about the tartrate buffered formulation now this is the one that merc is telling us supposedly has a mixture of tartrate and acetate it goes on in colum three lines one through four to say by switching to and acetate buffer so you had these tartrate examples and you switched to n s a t for that has to mean that the  it it creates a more stable climate you have less than the wanted degrades so this is this makes it attractive as a commercial product that's not to say that it says you can switch if you want or you can add more if you want but i'm still left with the claim that doesn't require something the decision to be added the fact that something can be added that you can add additional buffer doesn't mean you have to but if you look at the language it says by switching to an acetate buffer and the claim is to and acetate buffer that means the tartrate formulation didn't have an acetate up you went from that formulation and switched to one that does have an acetate buffer as claimed here and then you look at all of the examples and the examples nowhere refer to the tartrate examples as a mixed buffer they're talking about what you put in it you put in the active ingredient and tartrate or the active ingredient and acetate and the specification tells us at column eight lines sixty five through sixty seven it was surprisingly found that formulations one five seven and eight these are the ones that add acetate were significantly more stable and showed significantly less of an want it than the other formulations these are the ones with cartridge this is the only data in the entire path these are what they're referring to as the unexpected results that were the basis for the eighty nine it's the interview summary and the reasons for allowance the examiner tells us you've shown unexpected results and those unexpected results are in the specification show unexpected results compared to something you can't look at this and say there were unexpected results but we didn't compare everything you get everything in your specification the examiner was clearly looking at this saying you show unexpected results for one thing compared to another and the only two things in the back are tartrate and acetate and that's consistent with what the patent deep tells us at column eight lines sixty five through sixty seven the patentee says in the specification it was surprising it was unexpected these are the unexpected results the examiners looking at that the one with added tartrate showed column two lines twenty three three thirty again they're not talking about some stability the specification says the formulations of the invention language that would suggest a disclaimer provides and hants chemical stability to the formulation to the pharmaceutical compositions they're not talking about some stability relative to the active ingredient itself it says these have and hence the ability relative to some other composition and then they tell us two lines later that that other composition is the tartrate buffered formulation and the reason we end up with in the situation we're in here is because during the prosecution of this patent during the writing of this pat nobody paid any attention to the fact that when you take castle function by acetate and mix it with tartrate you get this dissociation and salt exchange that's not with this patent contemplated you can read this patent backwards forwards you can read the entirety of the prosecution there's not one word in there that suggest the tartrate example contains a mix but for this patent was looked at like a recipe and they said this is the active ingredient we put in this is the buffer and they said we want the added acetate buffer not the other buffers tartrate lactate phosphate and so they merely went on their way it wasn't until they had doing compas a product that used a different buffer a subsidy buffer that this theory comes to light that there is this salt exchange and oh yes the tartrate buffered examples are covered the rule is pretty strong against reading processes limitations into a product claim what case is strongest is for you to think to warrant an exception here well this is a case where like one of our own federal circuit opinions if i had to pick one life edwards life sciences sort of on page eight of my reply brief but this is a case where regardless of the standard no matter how exacting you say it is when you look at the entirety of the specification for the repeated statements that we switched to an acetate but for that the tertiary buffer doesn't give you enhanced ability that the acetate examples showed an enhanced ability and then the basis of the allowance being a comparison based on the claim yes you're on that would be the prosecution history for example if we go there and i'd like to also go through the reasons for allowing anything in the stat before we get to the prosecution history for the specifications read from the viewpoint of people still new york your honor in the salt exchange that we are talking about all the experts agree that occur so one person skilled the artist reading these examples they understand that when you put a tartrate buffer in to a system that has an acetate salt that the exchange six place and therefore all these examples have a mixed resulting in the generation of decker dates at a relatively high rate and you know as well as in counterpoint and out towards the end of the written description after going through all the examples the ones with the  showed significantly less of the unwanted decorative it's than the other formulations i e the tartrate formulation to me the comparison there it's pretty clear that what these people are happy about and what these people are i have discovered is that the use of an acetate buffer surprisingly they don't know why and they don't know how is producing a composition that is way more stable compared to yes which is titled detail description of the invention formulations of the invention provide in fancy chemical stability to the pharmaceutical companies compositions and then it says prior formulations been flying for tartrate buffer contain pharmaceutically significant amounts of unwanted gender equity ation the use of an acetate buffer results in the generation of fewer deprecates and a more stable formulation extended pharmaceutical shelf life offer significant economic advant prior formulations using a tartrate buffer had problems the inventions formulations using an acetate buffer has advantages all the way it actually goes around and says that the formulations were highly unstable they added a buffer meets element c and whether or not you have additional buffer doesn't matter because it's a comprising plan and that's what was going on with those target examples they mixed them they got better stability and they had to buffers in there so they ran test and the tests showed that the  not the thing that was doing it was making it worse so the claim is a broad claim to three elements one of which is an ascii buffer and we are not alleging we have never allege that tartrate buffer is an assett buffer we had to prove and we did prove that in new drug and they go on to describe this experiment with a at it more of the target a profit and they include it in addition increasing tartary concentration to one hundred million moles enhanced the instability and they go on and then add a course of the prosecution history was examined saying it's really obvious to use an acetate buffer to buffer these kinds of compositions and then your side kept pushing back and saying you know have you choose  to get the as a buffer to use it that you have to add in something that says on label asked a buffer you can put in for example sodium acetate that's not an essay proper it forms insitute so you're forming a box solution and you want to get a nasty buffer in there to get the benefits of why you get this great stability upon storage and storage is always done in a laugh life state so you are using a nasty buffer when you have this disorder the salt exchange took place and all the experts agreed on that that that  nasty buffer in it and it's going to give you the benefits you're using it at that point the other side said the reply brief that it says to formulate in the presence of acid buffer and we said well laugh ization that's part of the formulation you're using the active buffer f ization they said well that that's not part of the formulation but in fact the part of the specialization they rely on and that says it's part of your i've been talking about the pharmaceutical acceptable salts or are significantly more stable on storage this is in column t lines fifty four to fifty six they're more stable on storage when formulated in the presence of an assay buffer that in fact is the laugh lines formulation it's not a solution storage in this plan every single time a store to store  invention every degrees that takes place in fact their expert dr myrtle agreed when i cross examine same yes i agree that in fact will take place and that's at eight thirty four seventy nine eighty two that if i if i start with the salt of the tartra claim goes to the claim says you just have to have been asked a buffer it doesn't matter how you get there there's no display or saying that you have to do it via of certain process it just says get it in the ball solution if you have an essay buffer and it has an effective to provide the ph then you are in fact infringing  i will be brief i just want to make four quick points in response to judge shannon's earlier question about the case i was looking at a disclaimer case that's why i cited edwards on pages three and four of our reply brief we address the process issue and the non presidential sanofi case that they say makes clear that there are situations where you can in situations where you can't read a process limitation in if you want to call it that based on the spec the prosecution history the entirety of the intrinsic record  story that you just heard about this was the invention story and everybody knew it was a mixed buffer and everybody would have assumed it was the charge rate and a cite to j a thirty eight twelve prosecution history none of that's in the intrinsic record there isn't a statement anywhere in the prosecution history he was asked directly mirka doesn't have any statement to show a mixed buffer or to say that the tartrate example tartrate buffered examples that were relinquished and i would submit that on the entirety of the intrinsic record you cannot read the specification of this patent and the prosecution history and the exam or statement that of the active ingredient casco function by acetate mixed with a non acetate buffer like tartrate or sucks in a because if that is the case you cover the very tartrate examples that the intrinsic record makes clear were disappointed that the examiner said here there's a genus of buffers and he was very clear on thirty eight eighty nine of the joint appendix i'm not giving you the entire genus you get acetate has an unforeseen stabilizing effect the only two things in the specification are formulations that have the active ingredient casco function die acetate mixed with tar tree or cas sodium acetate and i forget what the other one is it's a column three second error there is another way of asking it is there can be multiple different ways when acetate buffer appears in the final composition but you're saying that this claim requires at least one particular way of getting there and that the by using an acid to buffer is among the yes the the prosecution history and the specification make clear you could mix two things to make an acetate buffer and then drop your active ingredient in it you could take your active ingredient and add acetate buffer to it what you can't do is take the active ingredient mix it with tartrate or mix it with sucks in eight and then say all that dissociated said forms an acetate buffer because that would encompass the very compositions the tartrate compositions but they said are covered and i would like to ask one issue one additional point and it's the issue of reverse versus remained there was a statement there brief that you would need to send this back to the district court to assess whether there is infringement should the court change the claim structure there is absolutely no dispute about our product zelie it takes castile fungi acetate they mix it with a six and eight six any a d that's what goes into it there's no separate acetate there's no chemicals that mix to form acetate everybody agrees what the product is so there's no need for remained and that's important because this patent expires in march of twenty