The State of Western Australia v Martinez
[2006] WASC 98
•20 MARCH 2006
JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA
IN CRIMINAL
CITATION: THE STATE OF WESTERN AUSTRALIA -v- MARTINEZ & ORS [2006] WASC 98
CORAM: EM HEENAN J
HEARD: 20 MARCH 2006
DELIVERED : 20 MARCH 2006
FILE NO/S: INS 150 of 2004
BETWEEN: THE STATE OF WESTERN AUSTRALIA
Prosecutor
AND
JOSE FELIX MARTINEZ
SALVATORE FAZZARI
CARLOS PEREIRAS
Accused
Catchwords:
Evidence - Voir dire - Opinion - Report of scientific expert upon cause of fall from bridge - Assumed facts underlying report in controversy - Methodology of analysis subject to criticism - Experimental procedures attempted to verify conclusion - No allowances for error
Legislation:
Nil
Result:
Evidence of opinion admissible
Category: B
Representation:
Counsel:
Prosecutor: Mr B Fiannaca SC & Mr S F Rafferty
First-named Accused : Mr S B Watters
Second-named Accused : Mr M J McCusker QC & Mr M J Bowden
Third-named Accused : Mr S D Freitag
Solicitors:
Prosecutor: State Director of Public Prosecutions
First-named Accused : Legal Aid Western Australia
Second-named Accused : Cannon Bowden & Co
Third-named Accused : Legal Aid Western Australia
Case(s) referred to in judgment(s):
Chamberlain v The Queen (No 2) (1984) 153 CLR 521
Clark v Ryan (1960) 103 CLR 486
Commissioner for Government Transport v Adamcik (1961) 106 CLR 292
HG v The Queen [1999] HCA 2; (1999) 197 CLR 414
Hocking v Bell (1945) 71 CLR 430
Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705
Mallard v The Queen (2003) 28 WAR 1
Mallard v The Queen [2005] HCA 68; (2005) 222 ALR 236
R v Bonython (1984) 38 SASR 45
R v Gilmore [1977] 2 NSWLR 935
R v Karger [2001] SASC 64
R v McHardie & Danielson [1983] 2 NSWLR 733
R v McIntyre [2001] NSWSC 311
Case(s) also cited:
Nil
EM HEENAN J: On Friday afternoon in the absence of the jury I received evidence on a voir dire from Dr Thomas James Gibson, the author of a report put forward by the solicitors for Mr Fazzari. Dr Gibson gave evidence by a video‑link connection with Sydney and was examined and cross‑examined on this report and associated evidence which counsel for Mr Fazzari desires to adduce in his defence later in this trial. The purpose of the hearing was to consider whether opinion evidence of the kind proposed was admissible in this case from Dr Gibson.
It is first necessary to say something about Dr Gibson's qualifications. He holds the degrees of Bachelor of Engineering, Master of Science and Doctor of Philosophy in engineering and has worked for a number of years in various institutions in the United States, in Canada, in South Australia and elsewhere in Australia in connection with product design, database analysis, and research, largely in connection with impact injuries upon the human body in a variety of situations, mainly motor vehicle accidents, and falls, but including other types of trauma.
His particular interest is accident reconstruction, crash simulation, automotive design, the design of safety equipment and database analysis, as a result of which he has given expert evidence in a number of forensic settings over the years. The focus of the report which he has prepared for these proceedings, dated 23 February 2006, is with the alleged fall of Phillip Walsham from the overhead footbridge at the Stirling train/bus interchange in the early hours of 28 February 1998.
The analysis which Dr Gibson has undertaken leads ultimately to the opinion which he has expressed in the report, at page 22, that the two most likely scenarios for the final position of Phillip Walsham on the roadway beneath the bridge are:
(1)that two men each of a stature greater than the 75th percentile, and significantly bigger than the accused who are said to be in the fifth percentile, threw the victim in a clean throw from the bridge;
(2)the victim made a voluntary dive from the ledge of the bridge.
In order to reach those ultimate conclusions Dr Gibson examined a number of possible fall scenarios which are itemised in par 4.4 of his report.
The first is that Mr Walsham was pushed over the rail. The conclusion in that respect of Dr Gibson was that, in his opinion, a fall of that type as a result of being pushed is not possible. The second was a voluntary dive from the bridge walkway, and in relation to that his conclusion was:
"To make this type of dive requires the victim to be running and then diving over a 1.04‑metre rail. This scenario is not possible with this type of dive. Given the stature of the victim and the height of the rail, it would not be possible to achieve a clean dive over the guardrail and the velocity necessary to achieve the required trajectory."
The third possible scenario is a voluntary dive from the bridge ledge; that is, on the far side of the rail. Dr Gibson's conclusion is:
"This scenario is possible and matches the observations of the eyewitness. This scenario is likely, especially in a forward dive."
In relation to the next possible scenario, being thrown over the bridge rail: as a result of experiments, which I will describe in more detail later, Dr Gibson reached the conclusion that men of the approximate stature of the accused, whom he assigns to the fifth percentile in stature - a conclusion itself which appears to be controversial - do not possess the combination of height and strength to achieve the required force.
The question is whether all or any of Dr Gibson's evidence can be admitted in these proceedings. In addressing this issue, I remind myself and acknowledge publicly that it is not for me at this stage to determine whether or not Mr Gibson's report is convincing or whether it is correct or demonstrably wrong. Those are decisions which, if they are to be made at all, can only be made by the tribunal of fact, namely, the jury.
My role at this stage of the proceedings is restricted to determining whether or not this qualifies as admissible expert evidence which may be led before the jury. If it is, then it can be criticised in anticipation by expert evidence from a witness or witnesses to be called for the prosecution, who may be asked to comment upon this thesis and the methodology, and Dr Gibson can, of course, be cross‑examined. That may lead to his evidence being accepted or rejected, enhanced, discredited or in other ways being refuted. Any of those processes will result in ultimate conclusions, as to whether or not to accept the evidence or to place any weight on it, being made by the jury.
So I must come to the question of whether or not, as asserted expert evidence, it may be admitted in these proceedings. A convenient summary of the tests for the recognition and admissibility of expert evidence in Australia can be found in the recent judgment of the Court of Criminal Appeal in the case of Mallard v The Queen (2003) 28 WAR 1 - the particular passages commence at 54, [251]. I will not cite all these passages but my observations can be taken to include and to adopt the observations of the Court of Criminal Appeal at [251] ‑ [252], where reference is made to the judgment of Dixon CJ in Clark v Ryan (1960) 103 CLR 486 at 491 and to the decision of King CJ in the Full Court of the Supreme Court of South Australia in R v Bonython (1984) 38 SASR 45 and through to [254] of Mallard.
In citing Mallard's case, I am of course aware that the actual decision of the Court of Criminal Appeal in Mallard's case was overturned by the decision of the High Court of Australia, Mallard v The Queen [2005] HCA 68; (2005) 222 ALR 236, but I do not consider that the successful appeal in the High Court called into question the tests for the recognition or acceptance of expert evidence which I have just described.
I come then to consider whether or not the methods adopted and applied by Dr Gibson constitute the application of a body of recognised skill, science or research and whether or not Dr Gibson is a person with the requisite skill, training or experience to express an opinion within the field of his expertise. In order to answer those questions it is necessary to scrutinise just what is being done or purported to being done by Dr Gibson in his report.
There are several phases to this process. Initially there is a description of facts, some uncontroversial, some controversial, about the circumstances of the accident leading to Mr Walsham's death. The next is an analysis of the physical injuries actually sustained which caused his death with a view to inferring the severity of those injuries so as to suggest the type of force which may have been involved in their occurrence. Neither of those two processes is controversial.
The next process is to investigate the so‑called mechanism of the injury which involves a hypothesis about the direction, trajectory and rate of fall of the body and Dr Gibson reached certain conclusions about how far the body fell, not merely vertically from the top of the bridge railing but also horizontally in reaching the position of the roadway some distance south of the railing.
In that respect, for reasons which I will describe more fully later, there are some very tendentious conclusions about how far the body fell and the direction of the trajectory. These are based on Dr Gibson's interpretation of other evidence, which I would expect to be challenged in the course of the case and if the challenges were to be successful that would undermine to some extent the conclusions which he has expressed.
Nevertheless, accepting the premises which have been adopted, doubtful though they may be, there is then an application of classical Newtonian mechanics to determine the velocity of the falling body and the duration of the fall. From these processes, which I accept are well‑established scientific applications, a conclusion is reached that the duration of the fall is 1.23 seconds; itself a conclusion which I would expect to be controversial.
If the period of the fall was 1.23 seconds it is then possible to calculate the velocity necessary for the body to move through the horizontal plane to the point where it was found on the ground and, hence, to infer the initial horizontal velocity in the component of the forces which led to the fall. By that process, once the weight or mass of the body which fell has been ascertained, it is possible to calculate the force operating in the horizontal plane which would account for that velocity.
The next step, and perhaps the most controversial step of all, is to translate from that calculated force the possibility of two young men of certain strengths being able to impart a sufficient force to a body in the course of a throw over the railing to account for that horizontal velocity and the position of the body on the ground below.
Dr Gibson's report does not, as far as I can see, explain exactly how this transition from inferred initial horizontal velocity to the force applied by assumed persons in the throw occurs to account for his theory.
To an extent, at 19 of the report, he relies on an experiment which was undertaken in an attempt to simulate possible scenarios of a throw of a body over a bridge in circumstances comparable with the present. There were 11 tests, two with three small males, which were not co‑ordinated and which produced no result, a number of other inconclusive tests, and the remainder led to the conclusion that it was not possible for the body to reach the position observed on the ground in a throw by two small males. Dr Gibson said in the course of his evidence that this confirmed conclusions which he had reached theoretically from the application of height and strength tables to which he had access but which were not included in his report, expressly identified or put forward for analysis. But it is this combination of height and strength tables in connection with an assumed background of familiarity with the strengths of small males, together with this experimental process, which is responsible for the essential conclusions in this report. The description which I have just undertaken should be sufficient to reveal how tenuous or controversial many of these conclusions are.
When one goes to the experimental process which was utilised by Dr Gibson to confirm his theoretical conclusions, one is also left with many reservations. This experimental process was captured, to an extent, on a video record, which forms part of the evidence which is to be led - an experiment conducted in Western Australia on 19 February 2006. It involves a simulation of the overhead footpath or footbridge with a railing of measured height identical to that which was found on the particular railing, and then there is a series of mats, rather like those found in a gymnasium for falling or vigorous exercise, upon which is measured a horizontal scale.
What happens then is that various combinations of young men seize a third person, usually by the legs, and throw him from the footbridge across the railing with as much force as they can exercise, and his fall is identified on the scaled mats, so that the trajectory can be plotted and extrapolated to the height of the actual footbridge in order to conclude where such a victim would have fallen on the ground had the bridge been of full height.
There are many approximations in this process: first of all, that there were two men involved and not three or one; secondly, that the victim was passive, exerting no resistance; and thirdly, that the mechanism of the throw was by simple elevation by one man on each leg. Those only have to be stated to indicate how subject to conjecture they are as a means of replicating what might have happened on the footbridge in the early hours of 28 February 1998. Be that as it may, it was an experiment with a certain degree of control designed to produce test results which were then employed to confirm the thesis postulated by Dr Gibson in his theoretical analysis.
One further feature of Dr Gibson's report is that there was no attempt made to standardise the results. There was no error analysis. All of the measurements actually relied upon, whether of height or of velocity or of weight, are fixed or precise measurements with no allowance, plus or minus, for error and they produce precise results, again with no variation for error. That does not impress even a lay observer as being particularly scientific but nevertheless that is the process.
In contrast in the tables to be found at page 20 Dr Gibson mentions that the quoted results for the velocities in the literature for a person making a forward dive or a backward dive come with an error component of plus or minus 17 per cent in the case of a forward dive and plus or minus 10 per cent in the case of a backward dive yet no such error allowance is made in the calculations which I have already described despite the many approximations involved in them. I will say more about the absence of error analysis a little later.
The next point about the experimental sequence followed by Dr Gibson is that there were very few experiments and not enough to justify an error analysis in Dr Gibson's own view. Next, all those which were relied upon involved two men throwing and not three and, as I have already said, absolute passivity by the victim. That accounts for a summary of Dr Gibson's report. I must now go back to the authorities.
Experiments are acceptable as evidence and are frequently utilised either alone or in combination with expert opinion evidence in many cases in the courts. The recent case of Mallard v The Queen (supra), which I have already described, refers to at least two species of experiment which were attempted in that case, the first being the pig's head experiment and the second being the salt water experiment, the first designed to see if the blows suffered by the victim could be replicated in an animal by the use of the suspected murder weapon and the second being a process to determine whether or not salts from river water could be washed out of clothing by heavy rain. These were both acknowledged by all the Justices in that case as being potentially relevant. Gummow, Hayne, Callinan and Heydon JJ endorsed the potential relevance of the pig's head experiment at [20] ‑ [22] and Kirby J acknowledged the potential relevance of both experiments at [56]. Each of the Justices treated the experimental results, even when they were inconclusive, as being relevant and potentially probative.
Similarly, in the celebrated case of Chamberlain v The Queen (No 2) (1984) 153 CLR 521 all the experiments conducted in that case were treated as potentially probative, even though, in retrospect, there was very great controversy as to their cogency. Some of the experiments relied upon by the prosecution in that case were methods of cutting the baby jumpsuit, a reconstruction of alleged blood flow in the front seat of the family car, the foetal haemoglobin experiment and what has been called the "zoo test" in which a dingo removing the carcass of a baby goat from a jumpsuit without tearing it was attempted under supervision. The conclusion was that the reliability of conflicting expert evidence in each of those instances were matters which should be left to the jury.
Further consideration of the principles relating to the admission of expert scientific opinion can be found in the decisions of R v Gilmore [1977] 2 NSWLR 935, R v McHardie & Danielson [1983] 2 NSWLR 733 and R v McIntyre [2001] NSWSC 311. These tests have been elaborately analysed and the authorities reviewed in a lengthy decision by Mullighan J in R v Karger [2001] SASC 64, unreported, dated 29 March 2001. That was a case involving a lengthy voir dire hearing not merely about the admissibility of DNA evidence but especially concerning the adequacy of the training of the particular witness to give expert opinion evidence about DNA techniques and testing methodology and, further, about the reliability of the particular experimental and analytical procedures used by the expert in that case.
Following the earlier authorities which I have already cited, Mullighan J admitted all the expert evidence, observing that the criticisms which went to its reliability either generally or, in the particular case, would be challenged on cross‑examination or by other evidence and that the weight or cogency of the evidence would be for evaluation by the jury. I particularly accept those passages in Karger's case in which this discussion was undertaken because it appears to me to be the most comprehensive discussion of these principles available in the literature which I could find in the brief time available to me.
The approach followed in Karger's case is consistent with a long line of authority which demonstrates that the resolution of conflicting evidence, even conflicting expert scientific evidence, is for the tribunal of fact - in this case, the jury - and not an issue affecting admissibility. That proposition can be found in the decision of the High Court in Commissioner for Government Transport v Adamcik (1961) 106 CLR 292 in the judgments of Windeyer and Menzies JJ and in the judgment of Dixon J, as he then was, in Hocking v Bell (1945) 71 CLR 430. There is however some limit upon this, which I will mention later.
I come now again to the evidence of Dr Gibson. His proposed evidence involves the application of generally accepted scientific principles to the formation of an opinion about the magnitude of the force or forces necessary to propel the body of the deceased, Phillip Walsham, from a narrow area of the overhead footbridge near the Stirling bus and train station to the position on the roadway below, where he was first found by the two taxi drivers who arrived at the scene, Messrs Bailey and Pilgrim. This involves the application of the classical principles of the physical laws of motion and dynamics to the measured dimensions of the scene in order to reach the conclusion stated.
There are a number of features of Dr Gibson's methods and assumptions which may render his conclusions questionable and the results tendentious. Among these are his premise that the body left the overhead footbridge at a point either beside the standard lamppost or, at the most, one metre to the west of that, meaning that it must have travelled a distance horizontally from the departure point of between 4.8 and 5.5 metres. Dr Gibson selects a figure of five metres rather than the distance of 3.7 metres measured at right angles from the edge of the railing to the position of the body on the roadway. This is demonstrated in figure 7 at page 16 of Dr Gibson's report and seems to be a very selective assumption. It is based on a particularly narrow interpretation of evidence given by the witness, Clare Pigliardo, both during the course of this trial and on earlier occasions.
Before I proceed to examine some of the weaknesses of that approach I should also add that the process followed by Dr Gibson also discloses his attitude to error analysis by seizing on the conclusion that the body left the bridge no more than one metre west of the lamppost. He measures a horizontal distance of between 4.8 metres and 5.5 metres to the point on the ground where the body was found and therefore selects for his velocity and force calculations a figure of five metres. Whereas we know that the body was found at a horizontal distance of 3.7 metres from the bridge, indicating that the area of uncertainty must be between 5.5 metres at a maximum and 3.7 metres as a minimum, thus indicating that if there is to be a mean, or a weighted mean, it would be significantly shorter than five metres and that a better prospective error analysis would be to take the estimate as ranging from 5.5 metres to 3.7 metres and building in a factor of error to the calculations. That has not been attempted.
The process of selecting the one metre band on the footbridge by Dr Gibson is almost entirely dependent upon fixing the point on the footbridge from which Phillip Walsham fell as being determined by a drawing on a photograph said to have been made by Ms Clare Pigliardo on an occasion out of court. This is very doubtful because Ms Pigliardo did not make any such drawing in evidence in this trial. The drawing which she did make, when questioned in the course of this trial about this point, clearly referred to a much wider area on the top of the footbridge than the one‑metre span selected by Dr Gibson, a point which would appear to be consistent with a fall involving a horizontal motion perpendicular to the bridge and with the body moving only about 3.7 metres in the horizontal plane. Next, it would seem to be very incongruent with the entirety of Ms Pigliardo's evidence, in the light of its context and her explanations, to treat it as being accurate to within the limit of no more than one metre, about the point where the body left the footbridge.
To assume such an order of accuracy is to assume a precision, which I doubt Ms Pigliardo ever intended or for that matter could be accepted as providing. Another premise in Dr Gibson's Newtonian analysis about the direction, dimensions and time of the falling body's trajectory is that it never reached a height greater than the top of the footbridge handrail; that is, the vertical distance of the fall was not greater than 7.4 metres. Yet a moment's reflection, or more pertinently, viewing the videotape of Dr Gibson's experiments shows that when a body is thrown over the rail it is first propelled upwards to clear the rail and travels in an arc and then descends from the apogee above the rail, all the while propelled by the horizontal component of the vector of forces applied.
This means that the horizontal force was acting from the point of release; that is, during the upward part of the arc traversed and also during the downward part when the 7.4 metres point was reached and passed in the descent. That is, more time was needed for such a trajectory than for a body falling from 7.4 metres. Small though the differences are, where the time for the duration of the fall is a function of the distance fallen, it may well be material. At least it would appear to be a reason to build in an additional allowance for error in the calculations because of this uncertainty, but this was not done.
Finally, all Dr Gibson's calculations as to time for the fall and distance covered are expressed in terms of absolute accuracy with no allowance for error plus or minus. This is most unlikely given the subjective nature of much of the data and renders questionable conclusions based on a difference between 3.7 metres and five metres over the short span of this fall.
I come to the next step in Dr Gibson's analysis. After inferring the initial horizontal velocity necessary to propel the body five metres rather than the 3.7 metres Dr Gibson concludes:
"This could not be achieved by two small men of the supposed stature of Messrs Fazzari and Pereiras and therefore the hypothesis that they threw him from the bridge is not possible."
This is based firstly on strength tables for men of various builds, heights and weights which were not specifically cited or annexed. It was also based on published figures for diving velocities but, as I have already mentioned, these included an error allowance of 10 per cent to 17 per cent. Finally it was based on the tests from the experimental simulations on the videotape which I have already described.
The hypothesis is that two and not three persons threw the victim, that there was no fight or struggle, that the victim was passive and made no contribution to the forces which impelled him off the bridge. This seems to be the most controversial area of the evidence and the point where reliability is most susceptible. There were only between three and eight tests in the experiment for lightweight men, there was only one test for the heavier men who were the throwers, there was no standardisation of the results nor stated allowances for error and the subjects being thrown were guarded and care was taken to prevent risk of injury to them.
Consequently, the ability of the experiment to reproduce actual or probable events which led to Mr Walsham being thrown, if that is indeed what happened, may well be speculative at best. However, these are all criticisms which seem to me to go more to weight than to admissibility.
I come now to the reservation which seems to be implicit in the more recent authorities about the admission of opinion evidence coming from an expert in a recognised area of science and I refer to the decision of the High Court of HG v The Queen [1999] HCA 2; (1999) 197 CLR 414, a case involving, among other issues, the question of whether or not a proposed expert report in a sexual assault case from a psychologist was admissible. The substance of the report was to the effect that the alleged assault on the young girl could not have been committed by the accused but must have been committed by another man some months before.
The learned trial judge excluded the so‑called expert evidence at trial on the grounds that it did not constitute scientific evidence. His decision was overturned on appeal when a retrial was ordered but, on a further appeal to the High Court of Australia, the decision of the trial judge was confirmed and the appeal by the prosecution was allowed. At [43] in the judgment of Gleeson CJ there is the passage:
"To paraphrase what was said by Dixon CJ in Clark v Ryan [(1960) 103 CLR 486] about the expert witness in that case, the evidence the defence sought to lead from Mr McCombie [the expert] really amounted to putting from the witness box the inferences and hypotheses on which the defence case wished to rely."
And at [44]:
"This was not a trial by jury, but in trials before judges alone, as well as in trials by jury, it is important that the opinions of expert witnesses be confined, in accordance with s 79, to opinions which are wholly or substantially based on their specialised knowledge. Experts who venture 'opinions', (sometimes merely their own inference of fact), outside their field of specialised knowledge may invest those opinions with a spurious appearance of authority, and legitimate processes of fact‑finding may be subverted. The opinions which Mr McCombie was to be invited to express appear to provide a good example of the mischief which is to be avoided."
That particular passage in the judgment of Gleeson CJ in the case of HG (supra) was followed and applied in the case of Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705, particularly in the judgment of Heydon J at 744. In that passage Heydon J, while speaking of the requirements for expert scientific evidence, said:
" ... it must be established that the facts on which the opinion is based form a proper foundation for it; and the opinion of an expert requires demonstration or examination of the scientific or other intellectual basis of the conclusions reached: that is, the expert's evidence must explain how the field of 'specialised knowledge' in which the witness is expert by reason of 'training, study or experience', and on which the opinion is 'wholly or substantially based', applies to the facts assumed or observed so as to produce the opinion propounded. If all these matters are not made explicit, it is not possible to be sure whether the opinion is based wholly or substantially on the expert's specialised knowledge. If the court cannot be sure of that, the evidence is strictly speaking not admissible, and, so far as it is admissible, of diminished weight."
In this case I am satisfied that Dr Gibson does have training, experience and expertise in the field of physics, mechanics and trauma analysis. I am satisfied that insofar as he purports to apply that established knowledge to the calculation of velocities, times and forces involved in this supposed fall, conventional scientific principles are applied. I do however have great reservations about the assumptions made in the process adopted by Dr Gibson, particularly as to the trajectory of the fall, the horizontal distance covered and the absence of allowance for error or error analysis.
I have a view, which is no more than a view, that there is a great degree of overprecision in this report which is not justified on the data, but despite the reservations which I have about this with regards to time, velocity and the conversion of velocity to force, it seems to me that those are matters which go to the weight which should be attributed to Dr Gibson's evidence rather than to its admissibility. Despite some initial reservations, it seems to me that the process by which he sets out to convert, from the initial horizontal velocity involved in the falling body to the force applied by the men or man on the top of the bridge is very questionable but it is, to an extent, based on an experiment which, despite some apparent inadequacies, can be evaluated by a tribunal of fact.
Consequently, I propose to allow the evidence of Dr Gibson to be led along the lines of the report which has been produced. Whether the report itself is wholly or entirely admissible will depend upon the course of the examination and the verification of the assumptions upon which it is premised. We will have to wait and see whether or not the report as a document, as distinct from the oral testimony of Dr Gibson, may be admissible.
Because the report depends so greatly on this experiment captured on the videotape I consider that the videotape must be regarded as part of the evidence and made available either as part of the evidence‑in‑chief or for use by any cross‑examiner, but I will not permit the audio component of the video to be played because it contains hearsay and gratuitous observations which, on any count, are inadmissible. So to the extent which I have endeavoured to explain, I will permit evidence in accordance with Dr Gibson's report and video to be adduced.
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