1.Introduction
Gauss once said "Mathematics is the queen of the sciences and number-theory the queen of
mathematics". That sets the mathematical tradition. One cannot cite a single instant in number
theory where an idea is borrowed from another science. All mathematical objects are by
implication the creation of the mind, not borrowed from any external phenomena, visual or
otherwise. On the other hand, empirical sciences have borrowed heavily from mathematics and
have greatly benefitted from it. Chaitin remarked that the usefulness of a hypothesis, and not
necessarily its "self-evident truth", is the key criterion by which to judge whether it should be
regarded as the basis for a theory [1]. Godel expressed in a discussion of Russell's
mathematical logic [2,3] that "...axioms need not be evident in themselves, but rather their
justification lies (exactly as in physics) in the fact that they make it possible for these sense
perceptions to be deduced... ". Here is a remark from Weyl in the same vein (1949): "A truly
realistic mathemtics should be conceived, in line with physics, as a branch of the theoretical
construction of the one real world, and should adopt the same sober and cautious attitude toward
hypothetic extensions of its foundations as is exhibited by physics." [4]. To these remarks, the
author adds: "We should not set number theory apart ... it should be treated as just another
science amongst sciences".
The author postulated back in 1988 that the point is divisible [11]. He pointed out that the axiom
of the indivisibility of the point was the cause of our inability to visualise beyond 3-dimensions.
To break this deadlock, the axiom itself must be changed. This is because visualisation is not
just an external phenomenon since it has a neurophysiological linkage from the external sceme
through our optic receptors to the visual cortex at the back of the brain. This is the basis of
visualisation the principle of which has been perfected by evolution some 65 million years ago
when warm blooded mammals played second strings to Dinosaurs by hunting at night with frontal
eyes and colour visions. Let me take the liberty to quote an excerpt from Geoffrey
Montgomery's The Mind's Eye from Discover [5]:
"....In 1968, ....two young neurobiologists at the University of Wisconsin found, to their surprise,
that the visual cortex was only one map among many. By probing the brain of the South
American owl monkey...... John Allman and Jon Kaas discovered that the back half of the
primate brain contains more than a dozen different maps of the visual field. Each one exists
within an area of the size of a postage stamp, and each displays the same scene, like television
sets arrayed in a department store, all turned to the same channel.
.... they encountered a lot of resistance and even hostility because people just couldn't
see what purpose these multple maps might be serving.....
Today, however, Allman, Kaas, and others have begun to figure out the purpose. As
they have monitored the reactions of neurons in the brains of monkeys, they have learned that
while these maps all show the same picture, they don't all accentuate the same aspects of it.
Cells in one map are particularly sensitive to motion. Cells in another respond strongly to
particular shapes. Those in a third respond to color. ... ".
Allman and Kaas' discovery pointed to an important geometrical principle -- the brain processes
a point as multiple points. In other word, our mind treat a point as divisible which is contrary to
the first definition established unchallenged by Euclid around 350 BC [6]. This fact was not
known to Euclid and could hardly be considered self-evident even in modern times. If Euclid had
defined the point as divisible, the course of scientific developments could have evolved
differently. The dice was cast and mathematics and sciences had marched on for more than
twenty centuaries since Euclid. Like the QWERTY keyboard invented more than a hundred years
ago during the industrial revolution, no one since has succeeded in replacing it by modern
keyboards.
Allman and Kaas' discovery is very relevant to geometry. Plane geometry was extended to
analytical solid geometry but that is a theoretical cul-de-sac due the assumption of the
indivisibility of points. Information since the advent of digital computers have become
multidimensional requiring innovative visualisation techniques. But a practical multidimensional
visualisation theory does not exist until the discovery of CAH [11]. CAH visualisation techniques
and point geometry have a nine years' history which eventually led to the development of
sequence algebra as a new offshoot in 1994 [7 to 15]. Sequence algebra is also called Visual
algebra although the former name is currently being used. This paper explains how number theory
could go multidimensional using sequence algebra. Left out entirely is the Hgram graph
since its plotting requires elaborate computer graphics in gif or jpg formats which creates bloated
HTML files [14]. This paper advocates the use of sequence algebraic graphs for the
visualisation of number theoretic functions. It should benefit mathematical communications via
the Internet.
2. Multidimensional Sequence Space
In conventional number theory, the natural number sequence is considered 1-dimensional. In
sequence algebra, sequences can be multidimensional. Given in table 1 are classifications of
dimensionalities of some well known number theoretic sequences:
---------------------------------------------------------------------------------------------------------------------------
Names Of Sequences..................................Number Of Dimensions
................................................Conventional Theory.................Sequence Algebra
----------------------------------------------------------------------------------------------------------------------------
Nat(z).......................................................1...............................................2
Even(z).....................................................1...............................................2
Odd(z)......................................................1...............................................2
Comp(z)...................................................1...............................................2
Prime(z)....................................................1...............................................2
Goldbach's sequence...............................nd...............................................3
Fermat's Last Theorem............................explicit but irrational.....................4
Mersenneprime(z) ....................................nef.............................................2
Fermatprime(z).........................................nef..............................................2
Twinprime(z)............................................nef..............................................3
---------------------------------------------------------------------------------------------------------------------------
Why are the first 5 primitive sequences considered 2-dimensional in sequence algebra?
Example 1 will explain why.
Example 1: Show that Nat(z) and Comp(z) are 2-dimensional. Show that Fermat's Last
Theorem is 4-dimensional.
All algebraic expansions are carried out using Maple V R 3.
Nat(z):=series(1/(z-1),z=infinity,8);
...........................................1......1......1......1......1......1...........1
..................Nat(z) := 1/z + ---- + ---- + ---- + ---- + ---- + ---- + O(----)...................(1).
.............................................2......3......4......5.......6......7..........8
...........................................z......z......z......z........z.......z...........z
A general term in Nat(z) takes the form k/z^i where i is considered plotted along the horizontal
cartesian axis and k ( = 1 here) is plotted along the vertical cartesian axis. This is equivalent to
the plotting of the expression k = f(i). Since both k and i appear on the RHS of equation (1), this
clearly can be interpreted as a 2D algebraic cartesian graph. Thus you can see that sequence
algebra is highly visual. Next have a look at Comp(z).
Comp(z):=series(1/(z^i*(z^i-1)),i=2..10),z=infinity,10);
................................................1..........2......2...........1..........1
.............................Comp(z) := ---- + ---- + ---- + ---- + O(---)..............................(2).
..................................................4..........6......8...........9.........10
................................................z..........z.......z...........z........z
Equation (2) can also be viewed as a 2-dimensional graph in sequence space. Fermat's Last
Theorem expressed in the form x^p + y^p = z^p contains four variable of which three can be
considered as independent at any one time. The sequence algebraic expression considers all
four as independent variables which can be varied over some ranges and plotted in a 4D-
sequence space.
FLT(x,y,z,p):=sum(sum(sum(sum(r^abs(i^m+j^m-k^m)/(x^i*y^j*z^k*
p^m),i=3..5),j=3..5),k=3..5),m=2..2);
In equation (3), five order variables are introduced with 4 in the denominator and 1 in the
numerator. The index to the r-variable is processed by an ABS( ) function to ensure the value
returned is positive. This keeps the r-variables always stationed in the numerators. The use of
the r-variable here is not as an indepedent variable but rather it is used to tag integer solutions
so that these can be distinguished from noninteger solutions. The four variables x,y,z, and p are
considered as independent variables. Hence the dimensionalities of FLT are counted as 4. You
can read off the actual values of x, y, and z from the first two terms in equation (3) which
represent Pythagorean primitive triplets of (4,3,5) and (3,4,5) for p = 2. Since p = 2 is uniform
throughout, one could dispense with the display of p and keep the sequence formulation down to
3 dimensions but this is retained here in case integer solutions for p > 2 are required.
.....................................................................9................16................25............16
.................................1.................1..............r..................r.................r................r
FLT(x, y, z, p) := ----------+----------+-----------+----------+-----------+-----------
............................4..3..5..2....3..4..5..2....3..3..3..2....4..3..3..2....5..3..3..2....3..4..3..2
..........................x..y..z..p......x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p
..................23.............32..............25..............32.............41............2
.................r................r................r..................r...............r...............r
......+.----------+----------+----------+----------+----------+----------
.........4..4..3..2.....5..4..3..2...3..5..3..2....4..5..3..2....5..5..3..2....3..3..4..2
........x..y..z..p......x..y..z..p....x..y..z..p....x..y..z..p......x..y..z..p....x..y..z..p
..............9................18.............9..............16..............25..............18
.............r.................r................r...............r.................r.................r
......+----------+----------+----------+----------+---------- +----------
..........4..3..4..2....5..3..4..2....3..4..4..2....4..4..4..2....5..4..4..2....3..5..4..2
.........x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p
...............25.............34..............9...............7................16.............9
..............r................r................r................r.................r................r
......+----------+----------+----------+----------+-----------+----------
.........4..5..4..2....5..5..4..2....5..3..5..2....4..4..5..2....5..4..5..2....3..5..5..2
........x..y..z..p.....x..y..z..p......x..y..z..p.....x..y..z..p.....x..y..z..p.....x..y..z..p
.................16............25...............7
...............r................r................r
......+-----------+.----------+------------ ................................................(3).
.........4..5..5..2....5..5..5..2....3..3..5..2
........x..y..z..p.....x..y..z..p......x..y..z..p
Example 2: Theorem (Division Algorithm): Given integers a and b, with b > 0, there exist unique
integers q and s satisfying a = q*b + s for 0 < s < b [6]. Verify this theorem using sequence
algebra.
In sequence algbebra, we compute s = a - q*b for various values of a, b and q in order to find the
useful range of s. to construct the general test term as r^(a-q*b)/z^abs(a-q*b) two order variables
called r and z are introduced one in the numerator and one in the denominator. The r-variable
will go to the denominator if its index expression is negative but otherwise it will stay in the
numerator. The z-order variable will always stay in the denominator because of the use of abs( )
function. Thus terms which satisfy the Theorem of Division Algorithm will be identified visually
by those having r in the numerators and z in the denominators and having the same exponent of s.
On the contrary, terms with both r and z in the denominators do not satisfy this theorem since the
index of r (=s) is negative. Computations are carried out for all three variables a,b, and q set to
the same upperbound of ub. The results are summarised in Table 1. The Division Algorithm
Theorem is validated by the results.
DIVALGM(a,b,q):=sort(sum(sum(sum(r^(a-q*b)/z^abs(a-q*b),
b=1..ub),a=1..ub),q=1..ub));
.................................................2......3......4
...............................................r.......r........r.....11.....9........9.........7.......7.........5
DIVALGM(a, b, q):=8r/z+5 ----+3----+----+---+-----+-----+-----+-----+-----
................................................2........3.......4...z.r....2..2....3..3....4..4.....5..5....6..6
..............................................z........z.......z.............z..r.....z..r....z..r......z..r.....z..r
...............7......5.........4..........4............5...........3............3.............3.............3..............2
.........+-----+-----+-----+-------+-------+-------+----------+---------+---------+---------
............7..7....8..8....9..9....10..10....11..11...12..12....13..13.....14..14.....15..15.....16...16
............z..r....z..r....z..r......z....r.......z....r......z....r........z.....r........z.....r.......z.....r......z.....r
..............2.............2..............2............1.............1.............1.............1..............1
.........+------- + ------- + ------- + ------- + ------- + ------- + ------- + ------- +10 .......(4).
..........17..17......18..18....19..19......20..20......21..21.....22..22.....23..23....24..24
.........z....r.........z....r......z.....r.......z.....r........z.....r.......z....r........z.....r......z....r
------------------------------------------------------------------------------------------------------------------------
Upperbound ub..............................Terms satisying Division Algorithm
------------------------------------------------------------------------------------------------------------------------
5............................................................................2...........3.........4
.............................................................................r............r..........r
.....................................................10 + 8 r/z + 5 ---- + 3 ---- + ------
..............................................................................2...........3.........4
.............................................................................z...........z.........z
6..........................................................................2............3..............4...........5
...........................................................................r.............r...............r...........r
...............................................14 + 10 r/z + 8 ---- + 5 ------ + 3 ------- + -------
..............................................................................2...........3.............4...........5
............................................................................z............z.............z...........z
..
7....................................................................2.............3.............4............5............6
.....................................................................r..............r..............r............r.............r
......................................16+ 14 r/z + 10 -------+ 8 ------+ 5 ------ + 3 -------+ -------
......................................................................2.............3.............4............5.............6
....................................................................z..............z.............z............z.............z
8......................................................2............3.............4.............5.............6............7
.......................................................r.............r..............r.............r..............r.............r
........................20+ 16 r/z + 14 -------+ 10 ---- + 8 ------ + 5 ------ + 3 ------ + ------
........................................................2............3..............4.............5.............6............7
.......................................................z............z.............z.............z..............z...........z
9......................................................2............3...........4............5.............6...........7..........8
.......................................................r.............r...........r............r..............r............r..........r
.........................23+ 20 r/z + 16 ---- + 14 ---- + 10 ---- + 8 ---- + 5 ---- + 3 ---- + ----
........................................................2..........3.............4.............5............6...........7..........8
.......................................................z..........z............z.............z............z...........z...........z
10..........................................2..........3............4..........5...........6.............7...........8..........9
............................................r...........r.............r...........r............r..............r............r..........r
..............27+ 23 r/z + 20 ---- + 16 ---- + 14 ---- + 10 ---- + 8 ---- + 5 ---- + 3 ---- + ----
..............................................2...........3...........4...........5...........6.............7...........8..........9
............................................z...........z...........z...........z...........z.............z............z.........z
--------------------------------------------------------------------------------------------------------------------------
Example 3: Theorem: Given integers a and b, not both of which are zero, there exist integers x
and y such that gcd(a,b) = ax+by [6]. Verify this theorem using sequence algebra.
The general testing term is constructed as shown: z^(gcd(a,b))/z^(a*x+b*y).
If gcd(a,b) = (a*x+b*y), then the numerator and the denominator expression exactly cancel
leaving a numerator 1. However, we do want to know what are the values of a,b,x, and y. So
we modify the test term as shown:
z^(gcd(a,b))/z^(a*x+b*y)*(a*b*x+a*b*y)/(r^a*s^b*p^x*q^y)
First of all, there is no indication from the above theorem that one should include negative
values of x and y. The author therefore programmed to search in the positive range of a, b, x and y.
Here is how the above test term is evaluated. If gcd(a,b) = (a*x+b*y), then z-variables will be
exactly cancelled. (a*b*x+a*b*y) is a filter term which will suppress displays of those terms where
either a or b is zero or x and y are both zero. The third bracketted denominator expression will
display the values of variables a,b,x and y used in solutions. Terms which satisfy the
theorem are those without z-variables in them. Using the Maple program line shown below,
a search for solutions was made for the upperbound ub ranged from 3 to 5. The findings are
summarised in Table 3. With just three trials, the solutions found already point to global
solutions given by:
sum(sum(1/(s*r^a*q)+ 1/(s^b*p*r), a=0..ub),b=0..ub) as the solutions to the theorem. The
number of solutions for each fixed value of ub is 2*ub. Solutions can only occur with either x or
y = 0 and both a and b are greater than 0. Solutions occur in image pairs for a and b. For
example in table 3, for ub = 3, the solutions are given by:
>sort(sum(sum(sum(sum(z^(gcd(a,b))/z^(a*x+b*y)*(a*b*x+a*b*y)/
(r^a*s^b*p^x*q^y),a=0..ub),b=0..ub),x=0..ub),y=0..ub);
For ub = 3: (a,b,x,y) = (1,1,1,0), (1,1,0,1),(1,2,1,0),(2,1,0,1),(1,3,1,0) and (3,1,0,1).
Every increase in the upperbound limit for ub wil bring in two more solution terms which are
given by: (1,ub,1,0) and (ub,1,0,1). We can thus predict the solutions globally by just follow this
pattern.
----------------------------------------------------------------------------------------------------------------
With ub = 3, only six terms satisfy this theorem:
.....................1...............1...............2...............2...............3..............3
..................-------- + --------+ ---------+ ---------+ --------- + ----------
...................s.p.r..........s.r.q.............2..............2.................3...........3
...................................................s.r...q..........s...p.r........s.r..q........s..p..r
With ub = 4, only 8 terms satisfy this theorem:
.....1........1............2..........2..............3..............3..............4...................4
----- + ----- + ------ + ------ + --------- + ---------+----------- + ------------
s p r....s r q...........2..........2...............3..............3..............4..................4
........................s.r...q.......s..p.r......s.r..q..........s..p.r......s.r..q..............s...p.r
With ub = 5, only 10 terms satisfy this theorem. Even with the ub for x and y raised to 10,
the solutions do not change. The solutions are dependent on the values of a and b only.
.....1..........1............2............2............3............3............4............4............5..............5
----- + ------- + -------- + ----- + ------ + ------ + ------- + --------+ ------- + ----------
s.p.r.......s.r.q..........2............2............3.............3............4...........4.............5..............5
...........................s.r...q.......s...p.r...s.r...q........s...p.r...s.r...q......s...p.r......s...r.q......s...p.r
-------------------------------------------------------------------------------------------------------------------------
Unfortunately, the results in table 3 do not include negative values of x and y. So another set of
computations allowing for negative values are computed and summarised in Table 4. From this
table it can be seen that values of a and b are positive whilst those of x and y are either of
opposite signs or one of them is a zero. These properties are not obvious from the proof of the
theorem.
but a and b are kept in the positive range with +ub limit only.
---------------------------------------------------------------------------------------------------------------
With ub = 3, only 18 terms satisfy this theorem:
(a,b,x,y):
(1,1,-2,3),(1,1,-1,2),(1,1,1,0),(1,1,2,-1),(1,1,3,-2),(1,1,0,1),(1,2,-3,2),(1,2,1,0),
(1,2,3,-1),(1,3,1,0),(1,3,-2,1),
(2,1,2,-3),(2,1,0,1),(2,1,-1,3),(2,3,2,-1).
(3,1,0,1),(3,1,1,-2),(3,2,-1,2),
-------------------------------------------------------------------------------------------------------------
With ub = 4, only 31 terms satisfy this theorem:
(a,b,x,y):
(1,1,-3,4),(1,1,-2,3),(1,1,-1,2),(1,1,1,0),(1,2,1,0),(1,2,-3,2),(1,1,2,-1),
(1,1,3,-2),(1,1,4,-3),(1,1,0,1),(1,2,3,-1),(1,2,4,-2),(1,3,1,0),(1,3,-2,1),
(1,3,4,-1),(1,4,-3,1),(1,4,1,0),
(2,1,0,1),(2,1,1,-2),(2,1,2,-3),(2,1,-1,3),(2,3,-4,3),(2,3,2,-1),
(3,1,-1,4),(3,1,0,1),(3,2,-1,2),(3,2,3,-4),(3,4,3,-2),
(4,1,0,1),(4,1,1,-3),(4,3,-2,3)
------------------------------------------------------------------------------------------------------------
With ub = 5, only 56 terms satisfy this theorem.
(a,b,x,y):
(1,2,-5,3),(1,2,-2,1),(1,3,-5,2),(1,2,-3,2),(1,1,-4,5),(1,1,-3,4),(1,1,-2,3),
(1,1,-1,2),(1,1,1,0),(1,1,2,-1),(1,1,3,-2),(1,1,4,-3),(1,1,5,-4),(1,2,1,0),
(1,2,3,-1),(1,3,1,0),(1,4,1,0),(1,5,1,0),(1,4,5,-1),(1,3,4,-1),(1,1,0,1),
(1,3,-2,1),(1,4,-3,1),(1,5,-4,1),(1,2,5,-2)
(2,1,0,1),(2,3,-4,3),(2,1,-1,3),(2,1,2,-3),(2,1,-2,5),(2,3,4,-3),(2,1,3,-5),
(2,5,3,-1),(2,3,2,-1),(2,5,-2,1)
(3,2,3,-4),(3,2,-1,2),(3,4,-5,3),(3,1,1,-2),(3,1,2,-5),(3,1,0,1),(3,1,-1,4),
(3,2,-3,5),(3,5,-3,2),(3,5,2,-1),(3,4,3,-2)
(4,3,-2,3),(4,3,4,-5),(4,1,-1,5),(4,5,4,-3)(4,2,1,-3),(4,1,1,-3),(4,1,0,1)
(5,2,1,-2),(5,1,1,-4),(5,4,-3,4),(5,2,-1,3),(5,3,-1,2),(5,3,2,-3),(5,1,0,1)
--------------------------------------------------------------------------------------------------------------
3. What Is Sequence Algebra?
Sequence algebra has a dual personality. When used in closed forms, holistic sequences can be
manipulated algebraically like algebraic variables within sequence generating functions. If all
sequences have unity values in the numerators, algebraic manipulations can be continued
indefinitely. When numerators increase beyond unities, such manipulations will fail. To remedy
this, the author introduced the operator Normc( ) which reduces all numerator coefficients to
unities if these are greater than unities [13]. However zero coefficients are not affected. This
operator ensures that algebraic manipulations can be continued as long as one wishes.
When sequence expanded, sequence algebra plots itself as a graph. This is not a cartesian
graph - it is actually an algebraic graph. It is more powerful than graphs in computer graphics
as it can be "plotted" using symbolic softwares. Thus one could switch functionality of sequence
algebraic expressions at will.
This paper demonstrates validation of elementary number theoretic theorems from classical
number theory. Often, algebraic proofs are not intuitive because these are too cryptic. One
could claim that these proofs contain all the information if one digs into them but such information
is not offered on a platter. Numerical investigations by sequence algebra often reveal more
information than can be gleaned from the proofs.
It might not be obvious how the divisibility of point enter into sequence algebra. It was
originally used in Hgram graphics [11 to 15]. Suppose one wishes to plot a 6D point, i.e.,
a point with 6 co-ordinate values given by P={1,2,3,4,5,6}. In Hgram graph, these six
values will be nested in pairs using brackets as shown: P={(1,2),(3,4),(5,6)} where
each bracketted pair represent a 2D-subpoint and when three subpoints are concatenated
we get a 6D-point. Thus there will be three subpoints to represent a 6D-point. This is what
is meant by the divisibility of a point. In sequence algebra, there is more flexibility in that
we simply represent points algebraically using order variables. There is no limitation
on the number of dimensions in this representation. It is more flexible than Hgram graphs.
4. Conclusions
This paper demonstrates multidimensional visualisation capability of sequence algebra. This is
a visual algebra which can plot itself using very modest softwares at one's disposal. Numerical
investigations can give insights which cryptic proofs may fail to reveal. Therefore, there is great
benefit for educators to teach number theory to beginners' classes using sequence algebra and
symbolic softwares. Although not mentioned, it is much easier to derive closed forms from
sequences by sequence algebra than via the Euler's form [1]. Mixed mode arithmetics is at
present not ideal and needs further development [9]. The author thinks that this is an area of
research which should be in the agenda of mathematicians into the 21st centuary.
4. References
1. Chaitin, J.G.: Randomness in Arithmetic, Scientific American, 259, No.1 (July 1988), pp. 80 -
85.
2.Chaitin, J.G.: Godel Theorem and Information, International Journal of Theoretical Physics 22
(1982), pp. 941-954.
3. Godel, K.: Russell's mathematical logic, and What is Cantor's continuum problem?, in
Philosophy of Mathematics, P. Benacerrf and H. Putnam (eds.), Prentice-Hall, Englewood Cliffs,
New Jersey, pp. 211-232, 258-273.
4. Weyl, H. (1949): Philosoophy of Mathematics and Natural Science, Princeton University
Press, Princeton, New Jersy.
5. Montgomery, G., (1991): Discover, May, 51-56. The Mind's Eye.
6. Burton M. Burton: Elementary Number Theory, Third Edition, WCB publishers, 1994, 17 to
23.
7. Huen Y.K.: A Simple Introduction To Sequence Algebra, a free downloadable paper available
from the author's URL site: http://web.singnet.com.sg/~huens/
8. Huen Y.K.: The Canonical Generating Function or CGF(z) - a Swiss-knife function. URL site:
http://web.singnet.com.sg/~huens/ .
9. Huen Y.K.: Information Contents Of Number Theoretic Functions. URL site:
http://web.singnet.com.sg/~huens/ .
10. Huen Y.K.: In Search Of Exotic Arithmetic Operators, URL site:
http://web.singnet.com.sg /~huens/ .
11. Huen Y.K.: An introduction to the HGRAM (an n-Dimensional Graph Paper). Copyright
application, July 1988, USA Library of Congress Copyright Registration No. Txu 354026.
12. Huen Y.K., Solihin, W., Loi K.S. and Allen R.M., (1991): Proceedings of the Third Triennial
Conference of the Association For Engineering Eduction In South-East Asia and The Pacific,
Christchurch, NZ.
13. Pok, Y.M., & Huen Y.K.: Visualiztion of hyperobjects by computers. Workshop Paper On
Modern Geometric Computing For Visualization (Springer-Verlag),1992, pp. 141-163.
14. Solihin Wawan, (1992)Graphical Optimization In Chemical Engineering Processes.
M.Eng. Thesis, Department Of Chemical Engineering, NUS.,1992.
15. Liyaw, A.P., Kiu, C.M., Pok Y.M., and Huen Y.K.: Hgram patterns of Routh stability zones
in linear systems. Int.J.Math.Educ.Sci.Technol., 1997, VOL., 28, NO.2, 225-241.
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