¹ [1982] RPC 183.

² Adopting the language used by Lord Hoffmann in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2004] UKHL 46 at [52].

³ These objects are expressly laid out in the Preamble to the Convention. It is in light of these objects that Patents Act 1977, s 130(7) provides that various sections of the Act are, ‘so framed as to have, as nearly as practicable, the same effects in the United Kingdom as the corresponding provisions of the [EPC]’. Lord Hoffmann, in Merrell Dow Pharmaceuticals v Norton [1996] RPC 76 at 82, declared it the duty of UK courts to construe these various sections, as far as possible, so as to give them the same effect as the corresponding articles of the EPC.

⁴ In this legal context the construction of claims is rarely straightforward, not least because outright duplication is a rare type of infringement; an observation made by the US Supreme Court in an argument directed to justifying recognition of a doctrine of equivalents in the USA: Graver Tank & Manufacturing v Linde Air Products, 339 US 605 (1950) at 607.

⁵ Lord Neuberger has noted that the drafting of the Protocol bears all the hallmarks of the product of a compromise agreement: Actavis v Eli Lilly [2017] UKSC 48 at [32]. See also the commentary in Pumfrey, N et al. ‘The doctrine of equivalents in various patent regimes – does anybody have it right?’ (2008) 11 Yale Journal of Law & Technology 261 at 307Google Scholar.

⁶ Aldous J, in AssiDoman v The Mead Corporation noted that, ‘[t]he middle ground referred to in the protocol is not clearly defined and every court within the Community had adopted a method of interpretation which it believes to be consistent with the protocol’: [1995] FSR 225 at 236. In BASF v Smithkline Beecham Sedley LJ observed that, ‘[t]here is nothing… in Article 69(1) as expounded by the Protocol which would not have been endorsed by the Victorian judges of our jurisdiction…’ [2003] EWCA Civ 872 at [104]. See also Empel, M van The Granting of European Patents (Leyden: Sijthoff, 1975) p 307Google Scholar (‘… it does not seem likely that many courts will admit that their decisions do not comply with this standard’); and White, T Blanco Patents for Inventions (London: Stevens & Sons, 4^th edn, 1974) pp 35–36Google Scholar (‘[Art 69 EPC] is a provision that will certainly allow both English and German courts to treat their respective national laws of infringement – which are very different – as conforming with the Convention’) and the more general commentary in M Fisher ‘New protocol, same old story? Patent claim construction in 2007; looking back with a view to the future’ (2008) Intellectual Property Quarterly 133.

⁷ The first opportunity for a full consideration of claims construction under the 1977 Act fell to Hoffmann J, in Improver Corp v Remington Consumer Products Ltd, who held that Lord Diplock's speech in Catnic indicated the same approach to construction as that laid down by the Protocol. This was later doubted by the Court of Appeal in PLG Research v Ardon International, Neill LJ expressing the hope that in future, ‘attention will be concentrated on the requirements of the protocol and the developing European jurisprudence and not on those of the common law before 1977’: [1995] FSR 116 at 133. Neill LJ's hopes were not realised however and in AssiDoman Multipack Ltd v The Mead Corporation, Aldous J held that purposive construction was the correct approach to construction under the Patents Act 1977 declaring himself loathe to discard 14 years of case law unless it was certain that this was not the correct approach: [1995] FSR 225 at 236. Adoption of the purposive approach was subsequently cemented by the Court of Appeal's holding in Kastner v Rizla that the Catnic test was to be applied when considering the ambit of a patent claim under the 1977 Act: [1995] RPC 585 at 594.

⁸ See Fisher, above n 6, at 150.

⁹ Ibid, at 141–142.

¹⁰ The amended version of the EPC came into force in December 2007.

¹¹ An observation made by Lord Kitchin in Icescape v Ice-World [2018] EWCA Civ 2219 at [59].

¹² [2017] UKSC 48.

¹³ [2017] UKSC 48 at [54]. Of course the great challenge is in deciding what makes a variation ‘immaterial’ since this requires consideration of the extent to which the scope of protection should extend beyond that dictated by the normal interpretation given to the words used in the claims: ibid at [56].

¹⁴ In particular the principles affirmed in Wood v Capita [2017] UKSC 24: ibid at [58].

¹⁵ [2017] UKSC 48 at [54].

¹⁶ This relationship is explored more fully in the following section.

¹⁷ Again a feature explored in the following section.

¹⁸ Coase, R ‘The problem of social cost’ (1960) 3 Journal of Law & Economics 1CrossRefGoogle Scholar.

¹⁹ (1894) 11 RPC 519 at 523.

²⁰ See for instance Lyle & Scott Ltd v Wolsey Ltd 1955 SLT 322 at 327; and Daily v Etablissements Fernand Berchet [1993] RPC 357 at 361.

²¹ Rockwater Ltd v Technip France SA (formerly Coflexip SA) [2004] EWCA Civ 381 at [42].

²² A relationship famously explored in Hohfeld, W ‘Fundamental legal conceptions as applied in judicial reasoning’ (1913) 23 Yale Law Journal 16CrossRefGoogle Scholar.

²³ [2004] UKHL 46 at [30]. Note also in this respect the dicta of Balcombe LJ in Daily v Etablissements Fernand Berchet [1993] RPC 357 at 361 (‘… the canons of construction of a patent are the same canons of construction that are to be applied to every written instrument that has to be construed by the court… It must, however, be a purposive rather than a purely literal construction…’).

²⁴ [2004] UKHL 46 at [31].

²⁵ See the comments of Lord Neuberger in Actavis [2017] UKSC 48 at [41].

²⁶ [2014] UKSC 2.

²⁷ [2014] UKSC 2 at [21].

²⁸ Ibid, at [20].

²⁹ [2017] UKSC 48 at [53].

³⁰ [2017] UKSC 24 at [13].

³¹ In the words of Lord Hoffmann, ‘… the words will usually have been chosen upon skilled advice. The specification is not a document inter rusticos for which broad allowances must be made’: Kirin-Amgen [2004] UKHL 46 at [34].

³² This can be seen as a contemporary manifestation of the assumption long adopted by courts that a patentee will have exercised care in setting out the limits of his claim and so will defer to the judgments made by the patentee. See for example Buckley LJ's judgment in Catnic in which he distinguishes between explicit directions given by the patentee and assumptions that a skilled reader might make: [1982] RPC 183 at 226–227.

³³ See Lord Neuberger's observations in Actavis [2017] UKSC 48 at [54].

³⁴ In the final section of this paper I develop the argument that equivalents should be taken into account in the construction of patent claims not only to give effect to the express demands of Article 2 of the Protocol but also because doing so acknowledges the costs and benefits of claims explicitly addressing a particular contingency.

³⁵ A broadly similar argument is advanced in Jamieson, C ‘In defence of a UK doctrine of equivalents’ (2019) 41 European Intellectual Property Review 147 at 150–151Google Scholar.

³⁶ [2017] UKSC 48 at [54].

³⁷ In contrast then to the second step of construction, which goes beyond this and considers the extent – if any – to which the scope of protection afforded by the claim should extend beyond that meaning: ibid at [56].

³⁸ See for example Generics (t/a Mylan) v Yeda Research and Development [2017] EWHC 2629 (Pat) at [138]; Illumina v Premaitha Health [2017] EWHC 2930 (Pat) at [201]–[202]; Fisher and Paykel Healthcare v ResMed [2017] EWHC 2748 (Ch) at [81]–[83]; and the Court of Appeal's decision in Icescape v Ice-World [2018] EWCA Civ 2219 at [60] and [96]. This decision by the Court of Appeal has cemented this interpretation: Coloplast v MacGregor Healthcare [2018] EWHC 2797 (IPEC) at [71]; and Eli Lilly v Genentech [2019] EWHC 387 (Pat) at [294].

³⁹ Eli Lilly v Genentech [2019] EWHC 387 (Pat) at [294].

⁴⁰ [2017] UKSC 48 at [53].

⁴¹ [2017] UKSC 48 at [57] citing in support Walton v Potter & Horsfall (1843) 1 WPC 585; and Clark v Adie (1877) 2 App Cas 315.

⁴² Laddie, H ‘Kirin Amgen – the end of equivalents in England?’ (2009) 40 International Review of Intellectual Property and Competition Law 3 at 14–18Google Scholar.

⁴³ Ibid, at 17–18.

⁴⁴ This focus is apparent in some of the earliest reported cases: see for instance Phillpott v Hanbury (1885) 2 RPC 33 at 38. The focus can also be defended in principle. As pertinently observed by Jeremy Waldron, ‘legal duties are hard things for people to have – since they constrain conduct and in that sense limit freedom – we should expect the realm of duties to be the testing ground for claims of right. The realm of duties – the propositions about duty that a given claim of right entails – is where we should expect the problems with the right (if there are any) to surface. It is true that not all the problems of a legal institution are connected with the duties it imposes. But the duties are a good place to start, since they will take us to whatever hardships are most intimately involved in the immediate recognition and enforcement of the rights’: Waldron, J ‘From authors to copiers: individual rights and social values in intellectual property’ (1992–3) 68 Chicago-Kent Law Review 841 at 844Google Scholar.

⁴⁵ (1877) 3 App Cas 34 at 44–45.

⁴⁶ (1894) 11 RPC 115 at 128.

⁴⁷ (1894) 11 RPC 519 at 532 and see also Automatic Weighing Machine v Knight (1889) 6 RPC 297.

⁴⁸ Keukenschrijver, A ‘The German practice’ in Pagenberg, J and Cornish, W (eds) Interpretation of Patents in Europe. Application of Article 69 EPC (Cologne: Carl Heymanns Verlag, 2006) p 91Google Scholar and to similar effect G Kolle ‘Interpretation of patents and the doctrine of equivalents’ (2007) OJ EPO Special edition 2/2007 –13th European Patent Judges’ Symposium 124, at 130. See also Fisher, above n 6, at 146–147.

⁴⁹ On which see Laddie, above n 42, at 10–11 and note also the comments of Lord Diplock in Beecham Group v Bristol Laboratories [1978] RPC 153 at 200 (‘The increasing particularity with which the claims are drafted and multiplied in modern specifications may have reduced the scope of application of the doctrine of pith and marrow, but I am unable to accept the argument… that this has made the doctrine obsolete. It still remains a part of patent law…’).

⁵⁰ [1963] RPC 61; Laddie, above n 42, at 19.

⁵¹ This distinguishes the case from the later decision of the House of Lords in Rodi & Wienenberger v Henry Showell [1968] FSR 100 where the differences were greater and there was more argument over the significance of those differences.

⁵² [1963] RPC 61 at 75.

⁵³ Cf Beecham Group v Bristol Laboratories [1978] RPC 153 in which the extraordinary finding that there could be equivalence of a claim to a product led to a unanimous holding of infringement. That decision is an outlier in other ways. As Laddie notes, ‘… it is a rare case of courts in the UK finding that the substitution of an essential feature of the claims did not avoid infringement. What Bristol had done made use of Beecham's inventive concept and the court was prepared to say that such use was colourable, even if it was outside the words of the claim’: Laddie, above n 42, at 22.

⁵⁴ [1963] RPC 61 at 76.

⁵⁵ [1963] RPC 61 at 77 (Viscount Radcliffe); and at 80 (Lord Devlin and Lord Hodson).

⁵⁶ [1963] RPC 61 at 80. A consequence of how the majority in Van der Lely approached the question of infringement was that in subsequent cases, ‘textual infringement’ and infringement of the ‘pith and marrow’ tended to be argued as separate causes of action; an outcome criticised and remedied by Lord Diplock nearly two decades later in Catnic, in which he expressed the view that there was no such dichotomy but a single cause of action: [1982] RPC 183 at 242.

⁵⁷ [1963] RPC 61 at 75 citing James LJ in Clark v Adie (1873) LR 10 Ch 667.

⁵⁸ For a more detailed account of this aspect of the Catnic decision see D Booton ‘How to be bad: the importance of perspective in intellectual property disputes’ (2018) Intellectual Property Quarterly 279.

⁵⁹ [1982] RPC 183 at 243.

⁶⁰ As noted in commentary made at the time of the decision, for instance: Annand, R ‘Infringement of patents – is ‘Catnic’ the correct approach for determining the scope of a patent monopoly under the Patents Act 1977?’ (1992) 21 Anglo-American Law Review 39 at 46Google Scholar. Laddie argues that as an example of the contextual approach to construing claims Catnic represented little more than a restatement of the old law together with the use of the expression ‘purposive construction’: Laddie, above n 42, at 23–24.

⁶¹ Codex Corporation v Racal-Milgo (1983) RPC 369 at 381–382.

⁶² [1982] RPC 183 at 243.

⁶³ Under which infringement ceased to be an issue determined according to common law – a change given added significance because, as noted above, the 1977 Act was enacted to bring the law of the UK into conformity with the corresponding provisions of the EPC.

⁶⁴ [1990] FSR 181 at 188–189.

⁶⁵ Laddie, above n 42, at 25.

⁶⁶ [2004] UKHL 46 at [45]–[48].

⁶⁷ Note in this respect the comments of Arnold J at first instance in Actavis [2014] EWHC 1511 (Pat) at [117] and of Lord Neuberger in the Supreme Court: [2017] UKSC 48 at [59].

⁶⁸ [2017] UKSC 48 at [56].

⁶⁹ As argued for instance by Crawford Jamieson: Jamieson, above n 35, at 150.

⁷⁰ See for instance the seminal account in Machlup, F An Economic Review of the Patent System. Study No 15 of The United States Subcommittee on Patent, Trade marks and Copyrights (Washington DC: US Government Printing Office, 1958) pp 77–78Google Scholar. See also Landes, W and Posner, R The Economic Structure of Intellectual Property Law (Cambridge, Mass: Belknap, 2003) pp 20–21Google Scholar; Posner, R Economic Analysis of Law (Austin: Wolters Kluwer Law & Business, 7^th edn, 2007) p 38Google Scholar; Guellec, D and B van Pottelsberghe de la Potterie The Economics of the European Patent System – IP Policy for Innovation and Competition (Oxford: Oxford University Press, 2007) p 4CrossRefGoogle Scholar; Epstein, R and Kieff, F ‘Questioning the frequency and wisdom of compulsory licensing for pharmaceutical patents’ (2011) 78 University of Chicago Law Review 71 at 72Google Scholar. There is considerably less accord when it comes to mapping insights about incentives onto legal doctrine: see for example Maurer, S ‘Ideas into practice: how well does US patent law implement modern innovation theory’ (2013) 12 John Marshall Review of Intellectual Property Law 643Google Scholar.

⁷¹ For a more complete review of contemporary and historical justifications of the patent system see Machlup, above n 70, pp 20–25 and from which the term ‘monopoly-profit-incentive’ is taken; and M Fisher ‘Classical economics and the philosophy of the patent system’ (2005) Intellectual Property Quarterly 1 at 6–24.

⁷² Wide-ranging empirical studies suggest that the negative impact of patent protection on prices and profits does not outweigh the advantages to the economy as a whole from having access to products dependent on patent protection: Taylor, C and Silberston, Z The Economic Impact of the Patent System – A Study of the British Experience (Cambridge: Cambridge University Press, 1973) p 334Google Scholar.

⁷³ [2015] UKSC 74 at [54]. The terms of the Protocol can similarly be seen as reflecting the same core economic concerns. As recently observed by Lord Sumption, ‘… claims fall to be interpreted, in accordance with the Protocol on the interpretation of Article 69 EPC, on a basis which “combines a fair protection for the patent proprietor with a reasonable degree of legal certainty for third parties.” What is fair or reasonable for these purposes falls to be considered in the light of the central objectives of this area of law’. Those objects, he said, included rewarding and incentivising complex and expensive processes of research and testing: Warner-Lambert v Generics (t/a Mylan) [2018] UKSC 56 at [82].

⁷⁴ For instance, Lord Hoffmann in Kirin-Amgen said, ‘[a]n invention is a practical product or process, not information about the natural world. That seems to me to accord with the social contract between the state and the inventor which underlies patent law. The state gives the inventor a monopoly in return for an immediate disclosure of all the information necessary to enable performance of the invention’: [2004] UKHL 46 at [77].

⁷⁵ For instance, in his account of the costs and benefits of the patent system, Fritz Machlup observes that, ‘… society would lose little or nothing if some inventors tried to guard their secrets, because few producers could succeed in doing so for very long and, moreover, similar ideas are usually developed by several people within a short time, if not simultaneously. The most cogent objection [rests] on a simple reflection: An inventor who, optimistically, thinks he need not fear that others would either find out his secret or come independently upon the same idea, will not go to the expense and trouble of taking a patent; he will disclose only what he fears cannot be kept secret’: Machlup, above n 70, p 24 [notes omitted].

⁷⁶ [2003] EWCA Civ 872 at [104] cited with approval by Lord Briggs in Warner-Lambert v Generics (t/a Mylan) [2018] UKSC 56 at [95]. Also notable are the comments of Lord UpJohn in Rodi & Wienenberger v Henry Showell who said that, ‘… it must be remembered that unlike a conveyance or a commercial document which is normally inter partes and must be interpreted, frequently very broadly, so far as possible to give effect to what appears to have been the intentions of the parties; a patent is a grant of a monopoly forbidding others to enter a part of the general commercial territory open to all of Her Majesty's subjects and so in the interests of those subjects that territory must be marked out with reasonable clarity by the claim, construing it fairly in the light of the relevant art’: [1968] FSR 100 at 121. Too similar effect see also the comments of Arnold J in Generics (UK) Ltd (t/a Mylan) v Yeda Research and Development Co Ltd [2017] EWHC 2629 (Pat) at [138] and those of Lord Kitchin in Icescape v Ice-World [2018] EWCA Civ 2219 at [60].

⁷⁷ Coase, above n 18.

⁷⁸ So far as property is concerned, Harold Demsetz famously developed a theory based around the argument that property rights arise when it becomes economic for those affected by externalities to internalise benefits and costs: Demsetz, H ‘Toward a theory of property rights’ (1967) 57 The American Economic Review, Papers and Proceedings of the Seventy-ninth Annual Meeting of the American Economic Association 347Google Scholar. Patents can be understood in similar terms: a property right in an invention enables inventors to internalise at least part of the social benefit arising from their invention as monopoly profits.

⁷⁹ Ogus, A Costs and Cautionary Tales: Economic Insights for the Law (Oxford: Hart Publishing, 2006) pp 74–76 and 86Google Scholar.

⁸⁰ Ibid, p 74. He goes on to note that as between individuals in similar circumstances, say two car drivers, it might be relatively easy to reach a solution, because presumably the hypothetical agreed duty would be a mutual level of care, hence reasonable care as prescribed by the law of negligence.

⁸¹ Of course this paints a rather simplified picture and each of these factors could be dissected to identify meaningful sub-factors. Whilst no doubt there are arguments which would benefit from a more nuanced analysis, this level of detail is sufficient to illustrate how bargaining between the parties leads to an efficient allocation of the burden of risk.

⁸² What form this consideration might take is considered below.

⁸³ Typically the costs of a research project cannot be recouped if a project fails because the assets utilised tend to be ‘idiosyncratic’ and cannot be redeployed without sacrifice of productive value. This is because a large proportion of R&D supports the salaries of research personnel: D Czarnitzki and A Toole ‘Patent protection, market uncertainty, and R&D investment’ (2006) ZEW – Centre for European Economic Research Discussion Paper No 06-056, available at http://ssrn.com/abstract=925621 (last accessed 30 July 2020) p 1; and Goel, R and Ram, R ‘Irreversibility of R&D investment and the adverse effect of uncertainty: evidence from the OECD countries’ (2001) 71 Economic Letters 287 at 288CrossRefGoogle Scholar.

⁸⁴ There is empirical evidence that supports that course of action being seen as rational by Firm B. Generally firms have a tendency to seek safeguards or ‘buffers’ against uncertainty: Langlois, R ‘The vanishing hand: the changing dynamics of industrial capitalism’ (2003) 12 Industrial and Corporate Change 351 at 354–355CrossRefGoogle Scholar. Furthermore, empirical studies have also shown that most large firm executives are risk adverse, see for example: MacCrimmon, K et al. Taking Risks: The Management of Uncertainty (New York: The Free Press, 1986) p 260Google Scholar.

⁸⁵ Outsourcing generally is a way for organisations to reduce costs and investment whilst focusing on what they do well: Doig, S et al. ‘Has outsourcing gone too far? (2001) 4 The McKinsey Quarterly 25Google Scholar. Of course the other side of this is that it allows organisations to avoid that which they don't do well. A key driver of any firm's decision to use markets to acquire a resource (a decision ‘to buy’) versus a decision to acquire that resource internally (a decision ‘to make’) is the set-up and transaction costs of making compared to buying: Coase, R ‘The nature of the firm’ (1937) 4 Economica 386CrossRefGoogle Scholar.

⁸⁶ Arrow, K ‘Economic welfare and the allocation of resources for invention’ in The Rate and Direction of Inventive Activity: Economic and Social Factors. A Report of the National Bureau of Economic Research (Princeton: Princeton University Press, 1962) p 613Google Scholar. Note also that ‘the outcome of any research project is necessarily uncertain and the most important results are likely to come from projects whose degree of uncertainty to begin with was greatest’: Arrow, K Essays in the Theory of Risk-Bearing (Amsterdam: North-Holland Publishing Co, 1974) p 138Google Scholar.

⁸⁷ Mansfield, E and Wagner, S ‘Organisational and strategic factors associated with probabilities of success in industrial R&D’ (1975) 48(2) The Journal of Business 179 at 190CrossRefGoogle Scholar.

⁸⁸ Kamien, M and Schwartz, N ‘Market structure and innovation: a survey’ (1975) 13 Journal of Economic Literature 1 at 2Google Scholar; and Blair, R and Cotter, T Intellectual Property. Economics and Legal Dimensions of Rights and Remedies (Cambridge: Cambridge University Press, 2005) pp 42–44CrossRefGoogle Scholar.

⁸⁹ Arrow (1962), above n 86, p 616.

⁹⁰ This is essentially the same as the problem of the communal ownership of land noted by Harold Demsetz: Demsetz, H ‘Toward a theory of property rights’ (1967) 57 The American Economic Review, Papers and Proceedings of the Seventy-ninth Annual Meeting of the American Economic Association 347 at 354–355Google Scholar.

⁹¹ Unless, of course, the parties can keep the invention secret which will be rare (see above).

⁹² Hence reasonable care as prescribed by the law of negligence: Ogus, above n 79, p 74.

⁹³ As a brief aside, it perhaps worth noting that the notion that the patent system serves a substitute for agreements between economically active entities explains why liability for infringement is limited to commercial activities: Patents Act 1977, s 60(5)(a).

⁹⁴ Although it is common for this not to be the case: V Narayanan and A Raman ‘Aligning incentives for supply chain efficiency’ (2009) (May) Harvard Business Review 94.

⁹⁵ Hence the condition that a patent may be granted only for an invention which is new: Patents Act 1977, s 1(1)(a).

⁹⁶ Hence the condition that a patent may be granted only for an invention which involves an inventive step: Patents Act 1977, s 1(1)(b).

⁹⁷ The conditions demanded of an invention if it is to be patentable: Patents Act 1977, s 1(1); EPC, Art 52.

⁹⁸ Kirin-Amgen [2004] UKHL 46 at [32].

⁹⁹ [2015] UKSC 74 at [55].

¹⁰⁰ Ibid, at [56].

¹⁰¹ Trump International Golf Club Scotland v The Scottish Ministers (Scotland) [2015] UKSC 74 at [33]–[35]. Lord Hodge was speaking specifically in relation to the interpretation of a consent to build a wind farm granted under the Electricity Act 1989, s 36, but makes clear earlier in his judgment that he understands these to be general rules on the interpretation of documents: ibid at [33].

¹⁰² The Moorcock, (1889) 14 PD 64 at 68. Bowen LJ's observations were described by Lord Neuberger as one of three classic statements as to the requirements which have to be satisfied before a term can be implied into a detailed commercial contract: Marks & Spencer v BNP Paribas Securities Services Trust [2015] UKSC 72 at [16].

¹⁰³ Marks & Spencer plc v BNP Paribas Securities Services Trust [2015] UKSC 72 at [15], citing in partial support Geys v Société Générale [2013] 1 AC 523 at [55].

¹⁰⁴ As reformulated by Lord Neuberger in Actavis [2017] UKSC 48 at [56].

¹⁰⁵ Marks & Spencer plc v BNP Paribas Securities Services Trust [2015] UKSC 72 at [21], citing in support Equitable Life Assurance Society v Hyman [2002] 1 AC 408 at 459. That the enquiry is a search for presumed rather than actual intention is justifiable as a means of reducing transaction costs. This argument is explained and developed below.

¹⁰⁶ [2015] UKSC 72 at [23], commenting on the earlier Privy Council decision in Attorney General of Belize v Belize Telecom [2009] UKPC 10.

¹⁰⁷ In the contract context is it not unusual for the same result to be arrived at by way of a correction by interpretation or by implication. See for example the comments of Lord Carnwath in Arnold v Britton [2015] UKSC 36 at [115].

¹⁰⁸ As put by Lord Steyn in Equitable Life Assurance Society v Hyman [2002] 1 AC 408 at 459.

¹⁰⁹ Arnold v Britton [2015] UKSC 36 at [18].

¹¹⁰ This then explains the view of the majority in Van der Lely [1963] RPC 61 considered above.

¹¹¹ [2015] EWCA Civ 555 at [72]. Arnold J at first instance employed similar reasoning: [2014] EWHC 1511 (Pat) at [131], [132], [145] and [149].

¹¹² [2017] UKSC 48 at [71]. Lord Neuberger observed that in this, the Court of Appeal and Arnold J at first instance were following the guidance given by Lord Hoffmann in Kirin-Amgen: ibid.

¹¹³ See the account of Lord Hodges in Wood v Capita [2017] UKSC 24 at [13], considered above.

¹¹⁴ Rational parties will weigh costs against benefits of explicitly addressing a particular contingency in the contract. If they believe the contingency unlikely to occur or otherwise its effects likely to be small then the contract may be insensitive to that contingency. For a more detailed analysis see: Ayres, I and Gertner, R ‘Filling gaps in incomplete contracts: an economic theory of default rules’ (1989) 99 Yale Law Journal 87 at 92–93CrossRefGoogle Scholar.

¹¹⁵ As observed by Lord Hoffmann in Kirin-Amgen [2004] UKHL 46 at [33].

¹¹⁶ Patents Act 1977, s 14(3). Furthermore, a patent may be revoked if the specification fails to disclose the invention clearly enough and completely enough for it to be performed by a person skilled in the art: Patents Act 1977, s 72(1)(c).

¹¹⁷ See for examples Raleigh Cycle v Miller (1948) 65 RPC 141 and Surface Silos v DCS Beal [1960] RPC 154.

¹¹⁸ As a result of the Patents (Amendment) (No 2) Rules 2016, it is not possible to include omnibus claims in UK patent applications unless this is the only way to define the technical features of the invention clearly and concisely. The problem addressed by this amendment is that the scope of protection of omnibus claims is often unclear since the description typically includes both inventive and non-inventive elements.

¹¹⁹ For example in order to obtain certain tax exemptions. Since 2013, in the UK a lower rate of corporation tax has been applicable to profits earned from patented inventions.

¹²⁰ See the discussion of Lord Morton in Raleigh Cycle v Miller (1948) 65 RPC 141 at 158–159. Immediately prior to the change to the Patents Rules that restricted their use, 35% of UK patent applications included such omnibus claims: Impact Assessment: changes to the Patents Rules 21/07/2016, available at https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/541239/Impact-Assessment-changes-to-the-Patents-Rules.pdf (last accessed 30 July 2020). On them being a common feature of UK practice see also the EPO Technical Board of Appeal decision: T 0150/82 (Claim Categories) reason 11.

¹²¹ For a fuller discussion see Biogen v Medeva [1997] RPC 1 at 47–49.

¹²² Borrowing the language used by Lord Hoffmann in Biogen v Medeva [1997] RPC 1 at 50.

¹²³ [1963] RPC 61 at 76 and considered above.

¹²⁴ See for instance the comments of Lord Hoffmann in Kirin-Amgen [2004] UKHL 46 at [35].

¹²⁵ [2017] UKSC 48, [88] and applied in Icescape v Ice-World [2018] EWCA Civ 2219 at [76]–[79].

¹²⁶ See Wood v Capita [2017] UKSC 24, considered above.

¹²⁷ Wood v Capita [2017] UKSC 24 at [13].

¹²⁸ Kirin-Amgen [2004] UKHL 46 at [35].

¹²⁹ Lee Tat Cheng v Maka GPS Technologies [2018] SGCA 18.

¹³⁰ Ibid, at [51].

¹³¹ [2017] UKSC 48 at [33].

¹³² [2004] UKHL 46 at [49].