Cite as:
Eric Allen Engle, Using WYSH Computer Programs to Model the Alien Tort Claims Act 6 Yale J. L. & Tech. 161 (2003-2004).
6 Yale J. L. & Tech. 161

Yale Journal of Law and Technology
CONTENTS
I.    WYSH: A DEDICATED COMPUTER PROGRAMMING LANGUAGE FOR ARTIFICIAL           
        INTELLIGENCE IN LAW ............................................... 162
II.   ARTIFICIAL INTELLIGENCE APPLICATIONS IN WYSH ........................ 161
      A.                          RULE BASED INFERENCE ENGINE (DEDUCTION) . 161
      B.                          CASE BASED INFERENCE ENGINE (INDUCTION) . 167
III.  PRACTICAL APPLICATIONS OF WYSH PROGRAMS: THE USE OF AI AS A TOOL TO      
        REDUCE LEGAL COMPLEXITY ........................................... 173
IV.   CONCLUSION AND FUTURE PROSPECTS ..................................... 173
 
*162 This paper argues that an artificial intelligence algorithm can model some of the principles of civil procedure. The binary conditionals used in civil procedure - e.g., personal jurisdiction exists/does not exist - correspond closely to the Boolean logic used by computers. Modeling procedural rules on a computer is thus possible and possibly useful. To illustrate this thesis, this paper applies the WYSH computer programming language to the Alien Tort Claims Act and Torture Victim Protection Act.

I. WYSH: A DEDICATED COMPUTER PROGRAMMING LANGUAGE FOR ARTIFICIAL INTELLIGENCE IN LAW 1

Since WYSH is an internet based application it is globally available. WYSH enables a lawyer anywhere to model any law quickly and accurately using a computer. WYSH is an inference engine. Many inference engines exist on the market today. 2 However, WYSH and PANNDA (one of WYSH's predecessors) are the only inference engines of which I am aware that specifically address the question of legal reasoning.
The WYSH engine is simple, globally accessible, and useful, though it does have some limitations. Any lawyer could easily learn to program in WYSH. Rulebases created in WYSH can be called from other rulebases anywhere in the world via the World Wide Web. WYSH also has an automatic English language parser, formats output and input dialogs automatically, and its output closely resembles standard English. Finally, WYSH is cost-free to users, thanks to the Australian National Research Council.

The WYSH engine automatically develops inferences from the rule base or case base which is supplied to it using forward chaining *163 and backward chaining. Because WYSH automatically chains the inferences for the programmer, it simplifies greatly the task of programming. Furthermore, the syntax of WYSH resembles BASIC and Pascal, whose syntax closely resembles standard English. Because of these facts, WYSH is highly accessible even to inexperienced programmers. A simple learning curve, tangible results, and global accessibility are why WYSH is worth investigating.

WYSH is a Perl program run through a common gateway interface (CGI). Therefore, a rule base can be made and hosted anywhere on the internet and call the WYSH CGI to process it. Further, different rule bases can call each other. Thus, in theory, several different jurists could develop different but interrelated rulebases in WYSH to represent whole areas of law. CGI's do however run less rapidly than a locally hosted program. Compiling also may be a cause of slow execution. Slow execution leads to frustration when testing and debugging rule bases because the CGI must compile the program for each and every execution of the rule base. Since WYSH is simply a web front end for the YSH inference engine it may be possible to obtain the YSH backend and use that for testing and debugging. I have not yet however found a source for the YSH program. YSH is currently being upgraded to a new program AIDE, 3 so some of the critiques and suggestions raised here may be being taken care of.

WYSH supports most simple control structures (IF ... THEN ... ELSE ... ELSE IF; FOR ... NEXT). End of line (return) rather than a semi-colon (;) indicates the conclusion of a statement. Function calls also are supported in WYSH. WYSH is not object oriented so FOR EACH is not supported. WYSH also does not have a Graphical User Interface. (GUI). I do not see either of these as serious limitations for the modelling of small rulebases.

WYSH uses a quasi English syntax which seems similar to BASIC. WYSH also automatically generates dialogues. WYSH rulebases should be "isomorphic", i.e. the text of a WYSH knowledge base should be as close as possible to the original legal text it models. In theory this isomorphism reduces the likelihood of typographical error or logical confusion and simplifies programmatic representation of law. Personally I find isomorphism neither a blessing nor a curse. However for new programmers isomorphism and automatic dialogue generation are strong points for WYSH because it can be an *164 introductory language for lawyers (i.e. non-programmers). This simplicity speaks for using WYSH as an introduction to computer intelligence in law.


II. ARTIFICIAL INTELLIGENCE APPLICATIONS IN WYSH
I have written one case base and several small rulebases using WYSH to simulate a court facing a claim under the Alien Tort Claims Act (ATCA) and/or the Torture Victim's Prevention Act (TVPA). I then ported the rulebases both as separate entities and as one entire overview to metaCard's Transcript scripting language, which was derived from Pascal / HyperTalk and also uses quasi-English for its instruction.

A. RULE BASED INFERENCE ENGINE (DEDUCTION)
The WYSH artificial intelligence engine allows the programmer to build either a rule base or a case base. A rule base is simply a series of rules that represent some area of knowledge - e.g., statutes. Rule based inferencing works via deduction - reasoning from general rules to specific cases. Deductive reasoning is the principle form of inference in the civil law. However, it is only a secondary form of reasoning in common law. Deduction does apply even within the common law to inferences from statutes. Thus, the rule based inference engine is better adapted to represent statutes. Case based reasoning in contrast reasons inductively from a series of known cases to the instant cases. Case based reasoning is appropriate for representing case-law.

The following rule bases simulate the findings that a court would meet under the Alien Tort Claims Act or Torture Victim's Protection Act. Note that each of these modules can be separately run under WYSH simply by copying the text, exactly as it appears, and pasting it into the WYSH manual start page. The beauty of the WYSH engine is that it automatically chains each of the rules in one rule base so that each of these modules is automatically interrelated without having to be explicitly called by the user. A rule set is declared in this way:

RULE ruleName PROVIDES
Statements
conclusion

*165 The following rules represent the Alien Tort Claims Act (ATCA), 4 the Torture Victim Protection Act (TVPA) 5 and various defenses developed in about a dozen cases. Each RULE indicator can run separately on the WYSH manual start page. 6 The entire rule base can be run as one whole.
 
RULE 'ATCA' PROVIDES                                                           
   IF     the defendant is an alien                                            
   THEN   IF    the tort is a violation of the law of nations                  
                OR                            the tort is a violation of a     
                                                treaty of the United States    
          THEN  U.S. courts have original jurisdiction                         
RULE TVPA PROVIDES                                                             
   IF     the defendant is an individual                                       
          AND   the plaintiff has exhausted their remedies in the foreign      
                  nation                                                       
          AND   the U.S. ten year statute of limitations has not tolled        
          AND   the plaintiff was subjected to torture or extrajudicial killing
          AND   the defendant had actual authority                             
                OR                            the defendant had apparent       
                                                authority                      
                OR                            the defendant acted under color  
                                                of law                         
   THEN   the defendant is liable in tort for the injuries to the plaintiff    
   ELSE   the defendant is liable in tort for the injuries to the plaintiff    
RULE 'tort defenses' PROVIDES                                                  
   IF     federal jurisdiction does not apply                                  
          OR    government immunity applies                                    
          OR    head of state immunity applies                                 
          OR    exhaustion applies                                             
          OR    comity applies                                                 
          OR    the claim is time barred                                       
          OR    forum non-conveniens applies                                   
          OR    political question doctrine applies                            
   THEN   defendant is not liable in tort                                      
   ELSE   defendant may be liable in tort                                      
RULE 'federal jurisdiction' PROVIDES                                           
   IF     subject matter jurisdiction applies                                  
          AND   personal jurisdiction applies                                  
   THEN   federal jurisdiction applies                                         
   ELSE   federal jurisdiction does not apply                                  
RULE 'in personam jurisdiction' PROVIDES                                       
   IF     specific jurisdiction applies                                        
          OR    general jurisdiction applies                                   
   THEN   in personam jurisdiction applies                                     
   ELSE   in personam jurisdiction does not apply                              
RULE 'general jurisdiction' PROVIDES                                           
   IF     defendant has systematic and continuous contacts to the United States
   THEN   general jurisdiction applies                                         
   ELSE   general jurisdiction does not apply                                  
RULE 'specific jurisdiction' PROVIDES                                          
   IF     original jurisdiction applies                                        
          OR    federal question applies                                       
   THEN   subject matter jurisdiction applies                                  
RULE 'original jurisdiction' PROVIDES                                          
   IF     general jurisdiction applies                                         
          OR    personal jurisdiction applies                                  
   THEN   IF    defendant is an alien                                          
          THEN  IF                            law of nations applies           
                                              OR the tort is a violation of a  
                                                treaty of the United States    
                THEN                          original jurisdiction applies    
                ELSE                          original jurisdiction does not   
                                                apply                          
RULE 'in personam' PROVIDES                                                    
   IF     defendant has systematic and continuous contacts to the United States
   THEN   general jurisdiction applies                                         
   ELSE   defendant has minimum contacts to the U.S.                           
     IF                                                                        
   THEN   IF    the tort occurred in the U.S.                                  
                OR                            the tort has effects in the U.S. 
          THEN  personal jurisdiction applies                                  
          IF    general jurisdiction applies                                   
          THEN  personal jurisdiction applies                                  
   IF     personal jurisdiction applies                                        
   THEN   'in personam' jurisdiction applies                                   
RULE 'law of nations' PROVIDES                                                 
   IF     the underlying tort arises out of piracy                             
          OR    the underlying tort arises out of genocide                     
          OR    the underlying tort arises out of an illegal war of aggression 
          OR    the underlying tort arises out of a crime against humanity     
          OR    the underlying tort arises out of a conspiracy to commit war of
                  aggression                                                   
          OR    the underlying tort arises out of a conspiracy to commit a     
                  crime against humanity                                       
          OR    the underlying tort arises out of a conspiracy to commit       
                  genocide                                                     
   THEN   the tort is a violation of the law of nations                        
   ELSE   the tort is not a violation of the law of nations                    
RULE 'FSIA' PROVIDES                                                           
   IF     the defendant is not a government                                    
   THEN   government immunity does not apply                                   
   IF     the defendant is a government                                        
   THEN   IF    there is an express waiver of governmental immunity            
                OR                            the act is purely commercial     
                                                (acto iure gestionis)          
          THEN  government immunity does not apply                             
          ELSE  government immunity applies                                    
RULE 'head of state immunity' PROVIDES                                         
   IF     the defendant is a head of state                                     
          OR    the defendant is a governmental minister                       
   THEN   the defendant is not liable                                          
   ELSE   IF    the defendant is still serving in their ministerial capacity   
          THEN  head of state immunity applies                                 
          ELSE  head of state immunity does not apply                          
RULE 'official immunity' PROVIDES                                              
   IF     the defendant is a civil servant                                     
          AND   the defendant is in the term of his office                     
          AND   the act is a ministerial act                                   
          AND   there is no waiver of immunity                                 
   THEN   official immunity does not apply                                     
   ELSE   official immunity applies                                            
RULE 'statute of limitations' PROVIDES                                         
   IF     the tort happens within the last ten years                           
          OR    equity tolls the statute of limitations                        
   THEN   the statute of limitations applies                                   
   ELSE   the statute of limitations does not apply                            
RULE 'forum non conveniens' PROVIDES                                           
   IF     this forum is oppressive to the defendant                            
          OR    this forum is an uneconomical choice when compared to competing
                  fora                                                         
   THEN   forum non conveniens applies                                         
   ELSE   the claim is barred by the statute of limitations                    
RULE 'act of state doctrine' PROVIDES                                          
   IF     the relief sought requires a U.S. court to declare invalid the       
            official act of a foreign sovereign performed in its own territory 
   THEN   act of state doctrine applies                                        
   ELSE   act of state doctrine does not apply                                 
RULE 'political question' PROVIDES                                             
   IF     the issue has been committed to the executive or legislature         
          OR    there are no judicially manageable standards                   
          OR    it is impossible to decide the case without also making a      
                  policy determination                                         
          OR    the case requires unquestioning adherence to a political       
                  decision already made                                        
          OR    the court risks causing potential embarrassment by creating    
                  multiple conflicting pronouncements from different branches  
                  of government                                                
   THEN   political question doctrine applies                                  
   ELSE   political question doctrine does not apply                           
RULE 'comity' PROVIDES                                                         
   IF     principles of fairness indicate that a foreign court would be more   
            appropriate                                                        
          OR    judicial economy indicates that a foreign court would be more  
                  appropriate                                                  
   THEN   comity applies                                                       
   ELSE   comity does not apply                                                
RULE 'color of law' PROVIDES                                                   
   IF     the non state actor fulfils a public function                        
          OR    the nexus of state and non-state actor connections are close   
          OR    the private sector was compelled by the state to act as it did 
          OR    the action was undertaken jointly                              
   THEN   The non state actor is considered to be a state actor for it operated
            under color of public law                                          
   ELSE   the non state actor is not considered to be a state actor for it did 
            not operate under color of public law.                             
 
*170 As we can see, this rule base is relatively complex. Logically, the first inquiry should be whether jurisdiction exists. We must then inquire whether a prima facie violation of the ATCA or TVPA exists. If so, we then consider the half dozen procedural defenses which defendants can raise to thwart such claims. If jurisdiction exists, and a prima facie tort exists under either the ATCA or TVPA, we then look at the defenses. If none of the defenses applies then a tort may exist.

B. CASE BASED INFERENCE ENGINE (INDUCTION)

A case base is a representation of a series of cases. Case bases permit the computer to reason inductively, from the case rules provided to determine the outcome in the case being determined. Basically a case base should summarize a series of relevant cases. The engine then reasons from the known cases to determine what the outcome would be in the case provided by the user. Inductive reasoning, inferring from known cases to determine the outcome in a new similar case, is the principal form of reasoning in the common law. This is a form of analogical reasoning: aspects of known cases are compared to those of a new case. If those aspects are similar then the same rule used in the old cases will apply to the new cases.

The WYSH engine includes case based reasoning. The singular brilliance of this engine is that it allows a weighted comparison of factually similar cases to be used to determine whether a rule does or does not apply to a given case.

The following is the listing of the case base used to determine whether a case constitutes a violation of either the Alien Tort Claims *171 Act or Torture Victim Protection Act. The code is fairly self explanatory. Each EXAMPLE is a new case in the case base. The names of the EXAMPLEs correspond to the name of cases litigating the ATCA or TVPA in U.S. courts. The conditionals (IF ... THEN) are so the same as in standard English.

GOAL RULE defendant may be liable PROVIDES DETERMINE defendant may be liable
 
EXAMPLE An v. Chun 7 PROVIDES                                            
defendant may not be liable                                                  
   IF  defendant was present in the United States                            
       AND  defendant was not a U.S. resident                                
       AND  defendant was not kidnapped                                      
       AND  defendant state asserted its right to immunity                   
       AND  defendant was a minister                                         
       AND  defendant was representing a state friendly to the United States 
       AND  defendant did not transact business in the United States         
       AND  defendant did not maintain an office in the United States        
       AND  defendant did not act as a commercial agent (acto jure gestionis)
       AND  defendant did not act as a sovereign (acto jure imperii)         
 
 
EXAMPLE Kadic v. Karadzic 8 PROVIDES                                     
defendant may be liable                                                      
IF  defendant was present in the United States                               
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was a minister                                            
    AND  defendant was not representing a state friendly to the United States
    AND  defendant did not transact business in the United States            
    AND  defendant did not maintain an office in the United States           
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE Filartiga v. Pena-Irala 9 PROVIDES                               
defendant may be liable                                                      
IF  defendant was present in the United States                               
    AND  defendant was a resident in the United States                       
    AND  defendant was not kidnapped                                         
    AND  defendant state did not assert its right to immunity                
    AND  defendant was a minister                                            
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did transact business in the United States                
    AND  defendant did maintain an office in the United States               
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE Amerada Hess 10 PROVIDES                                         
defendant may not be liable                                                  
IF  defendant was not present in the United States                           
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was a minister                                            
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did not transact business in the United States            
    AND  defendant did not maintain an office in the United States           
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE Sampson v. Germany 11 PROVIDES                                   
defendant may not be liable                                                  
IF  defendant was present in the United States                               
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was not a minister                                        
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did transact business in the United States                
    AND  defendant did maintain an office in the United States               
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE U.S. v. Noriega 12 PROVIDES                                      
defendant may be liable                                                      
IF  defendant was present in the United States                               
    AND  defendant was not a resident in the United States                   
    AND  defendant was kidnapped                                             
    AND  defendant state did not asserted its right to immunity              
    AND  defendant was a minister                                            
    AND  defendant was not representing a state friendly to the United States
    AND  defendant did transact business in the United States                
    AND  defendant did not maintain an office in the United States           
    AND  defendant did act as a commercial agent (acto jure gestionis)       
    AND  defendant did not act as a sovereign (acto jure imperii)            
EXAMPLE Doe v. Unocal Corp. 13 PROVIDES                                  
defendant may be liable                                                      
IF  defendant was present in the United States                               
    AND  defendant was a resident in the United States                       
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was not a minister                                        
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did transact business in the United States                
    AND  defendant did maintain an office in the United States               
    AND  defendant did act as a commercial agent (acto jure gestionis)       
    AND  defendant did not act as a sovereign (acto jure imperii)            
EXAMPLE Doe v. Unocal Corp. 14 PROVIDES                                  
defendant may not be liable                                                  
IF  defendant was not present in the United States                           
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was not a minister                                        
    AND  defendant was not representing a state friendly to the United States
    AND  defendant did transact business in the United States                
    AND  defendant did not maintain an office in the United States           
    AND  defendant did act as a commercial agent (acto jure gestionis)       
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE Saudi Arabia v. Nelson 15 PROVIDES                               
defendant may not be liable                                                  
IF  defendant was present in the United States                               
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was a minister                                            
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did transact business in the United States                
    AND  defendant did maintain an office in the United States               
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
EXAMPLE Amerada Hess 16 PROVIDES                                         
defendant may not be liable                                                  
IF  defendant was present in the United States                               
    AND  defendant was not a resident in the United States                   
    AND  defendant was not kidnapped                                         
    AND  defendant state asserted its right to immunity                      
    AND  defendant was not a minister                                        
    AND  defendant was representing a state friendly to the United States    
    AND  defendant did not transact business in the United States            
    AND  defendant did not maintain an office in the United States           
    AND  defendant did not act as a commercial agent (acto jure gestionis)   
    AND  defendant did act as a sovereign (acto jure imperii)                
 
*175 Again, as can be seen, the PANNDA engine forces us to consider each element of the case as having a value even where the facts were such that in the actual case no such value existed or was relevant. Similarly the UNOCAL case had to be split into two parts since it held that UNOCAL could be liable but SLORC could not. Further one could easily disagree with the characterizations I assigned to Doe v. Unocal (SLORC): was SLORC only engaging in a sovereign act? Or was it only a commercial actor? Or was it both a commercial and sovereign actor? Is Myanmar a regime friendly to the United States? Is it a regime unfriendly to the United States? Should that status even be considered? That factor - whether a foreign state is legally "friendly" to the United States - seems to be an example of creeping legal realism. A realist would note that in the cases where a close U.S. ally is involved liability is not found, but in cases where the locus delicti happens to be a state either not friendly to or even unfriendly toward the United States that liability is more likely to be found. In other words, simply because we can make a model of the law does not mean our model is necessarily right. That problem is compounded where debugging is hindered by the CGI's slow response *176 time. Slow CGI response time does force the programmer to be disciplined however and so is not entirely a bad thing.

III. PRACTICAL APPLICATIONS OF WYSH PROGRAMS: THE USE OF AI AS A TOOL TO REDUCE LEGAL COMPLEXITY

Lawyers would principally find WYSH and similar artificial intelligence useful for diagnostic work and more particularly as a way to avoid missing easy but obscure arguments. A well written WYSH program will force the lawyer to ask questions which s/he might otherwise overlook and thus raise potential defenses or lines of attack which they might not remember to raise at trial. For example, the civil procedure WYSH program will force the lawyer to remember each step in the determination of federal jurisdiction. These kinds of checklists already exist on paper of course but they may be more interesting if the lawyer is forced to go through them systematically and prompted to consciously formulate explicit answers to what might seem quite inconsequential factual questions. WYSH can also generate documents automatically (such as wills or contracts) based on user input. 17

IV. CONCLUSION AND FUTURE PROSPECTS

Computer applications in law have expanded from simple word processing to electronic research and trial aids (primarily animation). There have been relatively few applications of artificial intelligence to law. This is partly because AI is still a developing technology. Expert systems generally answer limited tasks reasonably well, but AI general systems have not yielded much success. AI, unlike other areas of programming, has not yet yielded profits. AI algorithms do increasingly figure in commercial programs. AI can be useful not only as a tool to teach legal reasoning to law students, but also as a source for automated document generation (principally contracts and wills) and "checklists" for legal practitioners.

a1. Eric Engle holds a J.D. from St. Louis Univ., a Diplôm d'Etudes Approfondies from l'Université Paris II, (Fiscalité, avec Mention) another D.E.A. from Paris X, Nanterre (Théorie du Droit) as well as an LL.M. in Europäisches Recht from the Universität Bremen where he works as a researcher and teacher at the Zentrum für Europäische Rechtspolitik. He is currently pursuing a doctorate in human rights law and an M.Sc. in Computer Science. He has a personal homepage at http://lexnet.bravepages.com. This article is offered in memoriam of Attorney Richard T. Kinnie and in condolences for the Kinnie family whose kindness and generosity opened my mind to the worlds of law and computers.

1. For a brief introduction to WYSH, see http:// www.austlii.edu.au/austlii/wysh (last visited ** Mar. 7, 2004).

2. For a list of open source AI interpreters, see http:// www2.cs.cmu.edu/afs/cs/project/ai-repository/ai/areas/expert/systems/0.html (last visited ** Mar. 7, 2004).

3. Caroline White, Artificial Intelligence to Give Lawyers a Run for Their Money, dotJournalism, May 3, 2001, at http://www.journalism.co.uk/ezine_ plus/dotjark/story231.shtml (last visited ** Mar. 7, 2004).

4. 28 U.S.C. § 1350 (1789).

5. Pub. L. No. 102-256, 106 Stat. 73 (1992).

6. See http://aide.austlii.edu.au/wysh/wyshstart.html (last visited ** Mar. 7, 2004).

7. 1998 U.S. App. Lexis 1303 (9th Cir. 1998).

8. 70 F.3d 232 (2d Cir. 1996).

9. 630 F.2d 876 (2d Cir. 1980).

10. Argentine Republic v. Amerada Hess Shipping Corp., 488 U.S. 428 (1989).

11. 250 F.3d 1145 (7th Cir. 2001).

12. 117 F.3d 1206 (11th Cir. 1997).

13. 248 F.3d 915 (9th Cir. 2001).

14. 248 F.3d 915.

15. 507 U.S. 349 (1993).

16. Amerada Hess, 488 U.S. 428.

17. See, e.g., http://www2.austlii.edu.au/~graham/wysh/wysh_will.html (last visited ** Mar. 7, 2004).