Introduction
Bi-graded linear operators (transformations) over n-dimensional vector spaces on a commutative ring . Members of this domain are morphisms . Products, permutations and composition (grafting) of morphisms are implemented. Operators are represented internally as tensors.
Operator composition and products can be visualized by directed graphs (read from top to bottom) such as:
n = 3 inputs
\ | / \ / / \ |
\ | / \/ / \ / \
\|/ \ / / \ / \
/ \ \/ / \ \ /
/ \ \ / / \ \ /
/ \ \ / / \ |
m = 2 outputs
Lines (edges) in the graph represent vectors, nodes represent operators. Horizontal juxtaposition represents product. Vertical juxtaposition represents composition.
See examples and documentation below
We try to start the right way by defining the concept of a monoidal category.
Ref: http://en.wikipedia.org/wiki/PROP_(category_theory)
spad
)abbrev category MONAL Monoidal
Monoidal(R:AbelianSemiGroup):Category == Monoid with
dom: % -> R
++ domain
cod: % -> R
++ co-domain
_/: (%,%) -> %
++ vertical composition f/g = g*f
apply:(%,%) -> %
++ horizontal composition
coerce:(x:List PositiveInteger) -> %
++ identity for composition and permutations of its products
coerce:(x:List None) -> %
++ [] = 1
add
(f:% / g:%):% == apply(g,f)
spad
Compiling FriCAS source code from file
/var/zope2/var/LatexWiki/5155383802378491972-25px001.spad using
old system compiler.
MONAL abbreviates category Monoidal
------------------------------------------------------------------------
initializing NRLIB MONAL for Monoidal
compiling into NRLIB MONAL
;;; *** |Monoidal| REDEFINED
Time: 0.03 SEC.
MONAL- abbreviates domain Monoidal&
------------------------------------------------------------------------
initializing NRLIB MONAL- for Monoidal&
compiling into NRLIB MONAL-
compiling exported / : (S,S) -> S
Time: 0.18 SEC.
(time taken in buildFunctor: 0)
;;; *** |Monoidal&| REDEFINED
Time: 0.01 SEC.
Cumulative Statistics for Constructor Monoidal&
Time: 0.19 seconds
finalizing NRLIB MONAL-
Processing Monoidal& for Browser database:
--------(dom (R %))---------
--------(cod (R %))---------
--------(/ (% % %))---------
--->-->Monoidal&((/ (% % %))): Improper first word in comments: vertical
"vertical composition \\spad{f/g} = \\spad{g*f}"
--------(apply (% % %))---------
--------(coerce (% (List (PositiveInteger))))---------
--->-->Monoidal&((coerce (% (List (PositiveInteger))))): Improper first word in comments: identity
"identity for composition and permutations of its products"
--------(coerce (% (List (None))))---------
--->-->Monoidal&((coerce (% (List (None))))): Improper first word in comments: []
"[] = 1"
--->-->Monoidal&(constructor): Not documented!!!!
--->-->Monoidal&(): Missing Description
; compiling file "/var/zope2/var/LatexWiki/MONAL-.NRLIB/MONAL-.lsp" (written 11 APR 2011 09:52:42 AM):
; /var/zope2/var/LatexWiki/MONAL-.NRLIB/MONAL-.fasl written
; compilation finished in 0:00:00.066
------------------------------------------------------------------------
Monoidal& is now explicitly exposed in frame initial
Monoidal& will be automatically loaded when needed from
/var/zope2/var/LatexWiki/MONAL-.NRLIB/MONAL-
finalizing NRLIB MONAL
Processing Monoidal for Browser database:
--------(dom (R %))---------
--------(cod (R %))---------
--------(/ (% % %))---------
--->-->Monoidal((/ (% % %))): Improper first word in comments: vertical
"vertical composition \\spad{f/g} = \\spad{g*f}"
--------(apply (% % %))---------
--------(coerce (% (List (PositiveInteger))))---------
--->-->Monoidal((coerce (% (List (PositiveInteger))))): Improper first word in comments: identity
"identity for composition and permutations of its products"
--------(coerce (% (List (None))))---------
--->-->Monoidal((coerce (% (List (None))))): Improper first word in comments: []
"[] = 1"
--->-->Monoidal(constructor): Not documented!!!!
--->-->Monoidal(): Missing Description
; compiling file "/var/zope2/var/LatexWiki/MONAL.NRLIB/MONAL.lsp" (written 11 APR 2011 09:52:42 AM):
; /var/zope2/var/LatexWiki/MONAL.NRLIB/MONAL.fasl written
; compilation finished in 0:00:00.020
------------------------------------------------------------------------
Monoidal is now explicitly exposed in frame initial
Monoidal will be automatically loaded when needed from
/var/zope2/var/LatexWiki/MONAL.NRLIB/MONAL
>> System error:
The bounding indices 163 and 162 are bad for a sequence of length 162.
See also:
The ANSI Standard, Glossary entry for "bounding index designator"
The ANSI Standard, writeup for Issue SUBSEQ-OUT-OF-BOUNDS:IS-AN-ERROR
The initial object in this category is the domain Prop (Products and Permutations).
spad
)abbrev domain PROP Prop
Prop(R:CommutativeRing): Join(Monoidal R, CoercibleTo OutputForm) with
_/:(R,R) -> %
== add
Rep == Record(domain:R,codomain:R)
rep(x:%):Rep == x pretend Rep
per(x:Rep):% == x pretend %
dom(f:%):R == rep(f).domain
cod(f:%):R == rep(f).codomain
coerce(f:%):OutputForm == dom(f)::OutputForm / cod(f)::OutputForm
(f:R / g:R):% == per [f,g]
apply(g:%, f:%):% ==
cod(f) ~= dom(g) => error "arity"
per [dom f,cod g]
(f:% * g:%):% == per [dom(f)+dom(g),cod(f)+cod(g)]
-- preserves arity
(f:% + g:%):% ==
dom(f)~=dom(g) or cod(g) ~= cod(g) => error "arity"
f
coerce(p:List PositiveInteger):% == per [#p::R,#p::R]
coerce(p:List None):% == per [0,0]
spad
Compiling FriCAS source code from file
/var/zope2/var/LatexWiki/785743822053201310-25px002.spad using
old system compiler.
PROP abbreviates domain Prop
------------------------------------------------------------------------
initializing NRLIB PROP for Prop
compiling into NRLIB PROP
compiling local rep : $ -> Record(domain: R,codomain: R)
PROP;rep is replaced by x
Time: 0.04 SEC.
compiling local per : Record(domain: R,codomain: R) -> $
PROP;per is replaced by x
Time: 0 SEC.
compiling exported dom : $ -> R
Time: 0 SEC.
compiling exported cod : $ -> R
Time: 0 SEC.
compiling exported coerce : $ -> OutputForm
Time: 0.01 SEC.
compiling exported / : (R,R) -> $
Time: 0 SEC.
compiling exported apply : ($,$) -> $
Time: 0.01 SEC.
compiling exported * : ($,$) -> $
Time: 0 SEC.
compiling local + : ($,$) -> $
Time: 0.01 SEC.
compiling exported coerce : List PositiveInteger -> $
Time: 0.06 SEC.
compiling exported coerce : List None -> $
Time: 0.01 SEC.
(time taken in buildFunctor: 0)
;;; *** |Prop| REDEFINED
;;; *** |Prop| REDEFINED
Time: 0 SEC.
Cumulative Statistics for Constructor Prop
Time: 0.14 seconds
finalizing NRLIB PROP
Processing Prop for Browser database:
--->-->Prop((/ (% R R))): Not documented!!!!
--->-->Prop(constructor): Not documented!!!!
--->-->Prop(): Missing Description
; compiling file "/var/zope2/var/LatexWiki/PROP.NRLIB/PROP.lsp" (written 11 APR 2011 09:52:43 AM):
; /var/zope2/var/LatexWiki/PROP.NRLIB/PROP.fasl written
; compilation finished in 0:00:00.111
------------------------------------------------------------------------
Prop is now explicitly exposed in frame initial
Prop will be automatically loaded when needed from
/var/zope2/var/LatexWiki/PROP.NRLIB/PROP
>> System error:
The bounding indices 163 and 162 are bad for a sequence of length 162.
See also:
The ANSI Standard, Glossary entry for "bounding index designator"
The ANSI Standard, writeup for Issue SUBSEQ-OUT-OF-BOUNDS:IS-AN-ERROR
The LinearOperator? domain is Moniodal over NonNegativeInteger?. It is the free algebra over Prop with n-generators.
Ref: http://en.wikipedia.org/wiki/Category_of_vector_spaces
- all members of this domain have the same dimension
- it might be useful (but much more complicated) to allow source
and target dimensions to be different
spad
)abbrev domain LIN LinearOperator
LinearOperator(dim:NNI,gen:OrderedFinite,K:CommutativeRing): Exports == Implementation where
NNI ==> NonNegativeInteger
T ==> CartesianTensor(1,dim,K)
Exports ==> Join(Ring, BiModule(K,K), Monoidal NNI, CoercibleTo Prop NNI) with
inp: List K -> %
++ incoming vector
inp: List % -> %
out: List K -> %
++ output vector
out: List % -> %
coerce: K -> %
arity: % -> Prop(NNI)
apply: (%,%) -> %
basisVectors: () -> List %
basisForms: () -> List %
tensor: % -> T
map: (K->K,%) -> %
ravel: % -> List K
unravel: (Prop NNI,List K) -> %
Implementation ==> add
import List NNI
import Prop NNI
Rep == Record(domain:NNI, codomain:NNI, data:T)
rep(x:%):Rep == x pretend Rep
per(x:Rep):% == x pretend %
dom(f:%):NNI == rep(f).domain
cod(f:%):NNI == rep(f).codomain
dat(f:%):T == rep(f).data
arity(f:%):Prop NNI == dom(f)/cod(f)
coerce(f:%):Prop NNI == arity f
0 == per [0,0,0]
basisVectors():List % == [per [0,1,entries(row(1,i)$SquareMatrix(dim,K))::T] for i in 1..dim]
basisForms():List % == [per [1,0,entries(row(1,i)$SquareMatrix(dim,K))::T] for i in 1..dim]
map(f:K->K, g:%):% == per [dom g,cod g,unravel(map(f,ravel dat g))$T]
ravel(g:%):List K == ravel dat g
unravel(p:Prop NNI,r:List K):% ==
dim^(dom(p)+cod(p)) ~= #r => error "failed"
per [dom(p),cod(p),unravel(r)$T]
--
-- f+g : A^{n+m} -> A^p = f:A^n -> A^p + g:A^m -> A^p
--
(f:% + g:%):% ==
dat(f)=0 => g
dat(g)=0 => f
dom(f) ~= dom(g) or cod(f) ~= cod(g) => error "arity"
per [dom f,cod f,dat(f)+dat(g)]
(f:% - g:%):% ==
dom(f) ~= dom(f) or cod(g) ~= cod(g) => error "arity"
per [dom f, cod f,dat(f)-dat(g)]
--
-- f/g : A^n -> A^p = f:A^n -> A^m / g:A^m -> A^p
-- g f : A^n -> A^p = g:A^m -> A^p * f:A^n -> A^m
--
apply(g:%,f:%):% ==
dom(g) ~= cod(f) => error "arity"
r:T := product(dat f, dat g)
g1:Integer:=dom(f)+1
f1:Integer:=dom(f)+cod(f)+1
for i in 0..cod(f)-1 repeat
r := contract(r,g1,f1-i)
per [dom(f),cod(g),r]
coerce(p:List PositiveInteger):% ==
r:=per([1,1,kroneckerDelta()$T])^#p
#p = 1 => return r
p1:List Integer:=[i for i in 1..#p]
p2:List Integer:=[#p+i for i in p]
p3:=concat(p1,p2)
per [#p,#p,reindex(dat r,p3)]
coerce(p:List None):% == per [0,0,1]
1:% == per [0,0,1]
coerce(x:K):% == 1*x
-- repeated product
(f:% ^ p:NNI):% ==
cod(f) ~= dom(f) => error "arity"
q:=subtractIfCan(p,1)
q case NNI => f^q * f
1
-- repeated sum
(p:NNI * f:%):% ==
q:=subtractIfCan(p,1)
q case NNI => q*f + f
0
(f:% * g:%):% ==
r:T := product(dat f,dat g)
-- dom(f) + cod(f) + dom(g) + cod(g)
p:List Integer := concat _
[[i for i in 1..dom(f)], _
[dom(f)+cod(f)+i for i in 1..dom(g)], _
[dom(f)+i for i in 1..cod(f)], _
[dom(f)+dom(g)+cod(f)+i for i in 1..cod(g)]]
-- dom(f) + dom(g) + cod(f) + cod(g)
--per [arity(f)*arity(g),reindex(r,p)]
per [dom(f)+dom(g),cod(f)+cod(g),reindex(r,p)]
(x:% = y:%):Boolean ==
dom(x) ~= dom(y) or cod(x) ~= cod(y) => error "arity"
dat(x) = dat(y)
(x:K * y:%):% == per [dom y, cod y,x*dat(y)]
(x:% * y:K):% == per [dom x,cod x,dat(x)*y]
(x:Integer * y:%):% == per [dom y,cod y,x*dat(y)]
inp(x:List K):% == per [1,0,entries(x)::T]
inp(x:List %):% ==
#removeDuplicates([dom(y) for y in x]) ~= 1 or
#removeDuplicates([cod(y) for y in x]) ~= 1 => error "arity"
per [(dom(first x)+1),cod(first x),[dat(y) for y in x]::T]$Rep
out(x:List K):% == per [0,1,entries(x)::T]
out(x:List %):% ==
#removeDuplicates([dom(y) for y in x])~=1 or
#removeDuplicates([cod(y) for y in x])~=1 => error "arity"
per [dom(first x),(cod(first x)+1),[dat(y) for y in x]::T]$Rep
tensor(x:%):T == dat x
coerce(x:%):OutputForm ==
dom(x)=0 and cod(x)=0 => return dat(x)::OutputForm
gens:List OutputForm:=[index(i::PositiveInteger)$gen::OutputForm for i in 1..dim]
-- input basis
inps:List OutputForm := []
for i in 1..dom(x) repeat
empty? inps => inps:=gens
inps:=concat [[hconcat(inps.k,gens.j) for j in 1..dim] for k in 1..#inps]
-- output basis
outs:List OutputForm := []
for i in 1..cod(x) repeat
empty? outs => outs:=gens
outs:=concat [[hconcat(outs.k,gens.j) for j in 1..dim] for k in 1..#outs]
-- term list
bases:List OutputForm:=[]
coeffs:=ravel dat(x)
if #inps > 0 and #outs > 0 then
expon:List List OutputForm:=concat([[[i,j] for j in outs] for i in inps])
bases:=[scripts('e::OutputForm,ij) for ij in expon]
else if #inps > 0 then
bases:=[sub('e::OutputForm,i) for i in inps]
else if #outs > 0 then
bases:=[super('e::OutputForm,j) for j in outs]
terms:=[(k=1 => base;k::OutputForm*base) for base in bases for k in coeffs | k~=0]
empty? terms => return 0::OutputForm
return reduce(_+,terms)
spad
Compiling FriCAS source code from file
/var/zope2/var/LatexWiki/2028892082900829065-25px003.spad using
old system compiler.
LIN abbreviates domain LinearOperator
------------------------------------------------------------------------
initializing NRLIB LIN for LinearOperator
compiling into NRLIB LIN
importing List NonNegativeInteger
importing Prop NonNegativeInteger
compiling local rep : $ -> Record(domain: NonNegativeInteger,codomain: NonNegativeInteger,data: CartesianTensor(One,dim,K))
LIN;rep is replaced by x
Time: 0.04 SEC.
compiling local per : Record(domain: NonNegativeInteger,codomain: NonNegativeInteger,data: CartesianTensor(One,dim,K)) -> $
LIN;per is replaced by x
Time: 0 SEC.
compiling exported dom : $ -> NonNegativeInteger
Time: 0 SEC.
compiling exported cod : $ -> NonNegativeInteger
Time: 0 SEC.
compiling local dat : $ -> CartesianTensor(One,dim,K)
Time: 0 SEC.
compiling exported arity : $ -> Prop NonNegativeInteger
Time: 0 SEC.
compiling exported coerce : $ -> Prop NonNegativeInteger
Time: 0 SEC.
compiling exported Zero : () -> $
Time: 0.01 SEC.
compiling exported basisVectors : () -> List $
Time: 0.03 SEC.
compiling exported basisForms : () -> List $
Time: 0.12 SEC.
compiling exported map : (K -> K,$) -> $
Time: 0.04 SEC.
compiling exported ravel : $ -> List K
Time: 0 SEC.
compiling exported unravel : (Prop NonNegativeInteger,List K) -> $
Time: 0.02 SEC.
compiling exported + : ($,$) -> $
Time: 0.01 SEC.
compiling exported - : ($,$) -> $
Time: 0 SEC.
compiling exported apply : ($,$) -> $
Time: 0.01 SEC.
compiling exported coerce : List PositiveInteger -> $
Time: 0.03 SEC.
compiling exported coerce : List None -> $
Time: 0.01 SEC.
compiling exported One : () -> $
Time: 0 SEC.
compiling exported coerce : K -> $
Time: 0.01 SEC.
compiling exported ^ : ($,NonNegativeInteger) -> $
Time: 0.01 SEC.
compiling exported * : (NonNegativeInteger,$) -> $
Time: 0 SEC.
compiling exported * : ($,$) -> $
Time: 0.01 SEC.
compiling exported = : ($,$) -> Boolean
Time: 0.01 SEC.
compiling exported * : (K,$) -> $
Time: 0 SEC.
compiling exported * : ($,K) -> $
Time: 0 SEC.
compiling exported * : (Integer,$) -> $
Time: 0 SEC.
compiling exported inp : List K -> $
Time: 0.01 SEC.
compiling exported inp : List $ -> $
Time: 0.03 SEC.
compiling exported out : List K -> $
Time: 0.01 SEC.
compiling exported out : List $ -> $
Time: 0.01 SEC.
compiling exported tensor : $ -> CartesianTensor(One,dim,K)
Time: 0.01 SEC.
compiling exported coerce : $ -> OutputForm
Time: 0.12 SEC.
(time taken in buildFunctor: 0)
;;; *** |LinearOperator| REDEFINED
;;; *** |LinearOperator| REDEFINED
Time: 0.02 SEC.
Warnings:
[1] not known that (CommutativeRing) is of mode (CATEGORY domain (SIGNATURE quo ($ $ $)) (SIGNATURE rem ($ $ $)) (SIGNATURE gcd ($ $ $)) (SIGNATURE divide ((Record (: quotient $) (: remainder $)) $ $)) (SIGNATURE exquo ((Union $ failed) $ $)) (SIGNATURE shift ($ $ (Integer))) (SIGNATURE random ($ $)))
[2] arity: not known that (CommutativeRing) is of mode (CATEGORY domain (SIGNATURE quo ($ $ $)) (SIGNATURE rem ($ $ $)) (SIGNATURE gcd ($ $ $)) (SIGNATURE divide ((Record (: quotient $) (: remainder $)) $ $)) (SIGNATURE exquo ((Union $ failed) $ $)) (SIGNATURE shift ($ $ (Integer))) (SIGNATURE random ($ $)))
[3] coerce: bases has no value
Cumulative Statistics for Constructor LinearOperator
Time: 0.57 seconds
finalizing NRLIB LIN
Processing LinearOperator for Browser database:
--------(inp (% (List K)))---------
--->-->LinearOperator((inp (% (List %)))): Not documented!!!!
--------(out (% (List K)))---------
--->-->LinearOperator((out (% (List %)))): Not documented!!!!
--->-->LinearOperator((coerce (% K))): Not documented!!!!
--->-->LinearOperator((arity ((Prop NNI) %))): Not documented!!!!
--->-->LinearOperator((apply (% % %))): Not documented!!!!
--->-->LinearOperator((basisVectors ((List %)))): Not documented!!!!
--->-->LinearOperator((basisForms ((List %)))): Not documented!!!!
--->-->LinearOperator((tensor (T$ %))): Not documented!!!!
--->-->LinearOperator((map (% (Mapping K K) %))): Not documented!!!!
--->-->LinearOperator((ravel ((List K) %))): Not documented!!!!
--->-->LinearOperator((unravel (% (Prop NNI) (List K)))): Not documented!!!!
--->-->LinearOperator(constructor): Not documented!!!!
--->-->LinearOperator(): Missing Description
; compiling file "/var/zope2/var/LatexWiki/LIN.NRLIB/LIN.lsp" (written 11 APR 2011 09:52:44 AM):
; /var/zope2/var/LatexWiki/LIN.NRLIB/LIN.fasl written
; compilation finished in 0:00:00.883
------------------------------------------------------------------------
LinearOperator is now explicitly exposed in frame initial
LinearOperator will be automatically loaded when needed from
/var/zope2/var/LatexWiki/LIN.NRLIB/LIN
>> System error:
The bounding indices 163 and 162 are bad for a sequence of length 162.
See also:
The ANSI Standard, Glossary entry for "bounding index designator"
The ANSI Standard, writeup for Issue SUBSEQ-OUT-OF-BOUNDS:IS-AN-ERROR
Consult the source code above for more details.
Basis
axiom
dim:=2
axiom
L:=LinearOperator(dim,OVAR [x,y],FRAC POLY INT)
Type: Type
axiom
Dx:=basisVectors()$L
Type: List(LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer))))
axiom
dx:=basisForms()$L
Type: List(LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer))))
axiom
matrix [[dx.i * Dx.j for j in 1..dim] for i in 1..dim]
Type: Matrix(LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer))))
axiom
matrix [[Dx.i / dx.j for j in 1..dim] for i in 1..dim]
Type: Matrix(LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer))))
Conveniences
axiom
macro Σ(x,b,i)==reduce(+,[x*b.i for i in 1..dim])
Type: Void
axiom
macro /\(x,s)==superscript(x,s)
Type: Void
axiom
macro \/(x,s)==subscript(x,s)
Type: Void
Construction
axiom
A1:L := Σ(a1\/[i],dx,i)
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity A1
Type: Prop(NonNegativeInteger
?)
axiom
A2:L := Σ(a2\/[i],dx,i)
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
A:L := inp[A1,A2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity A
Type: Prop(NonNegativeInteger
?)
axiom
B1:L := Σ(b1/\[i],Dx,i)
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity B1
Type: Prop(NonNegativeInteger
?)
axiom
B2:L := Σ(b2/\[i],Dx,i)
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
B:L := out[B1,B2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity B
Type: Prop(NonNegativeInteger
?)
axiom
B:L := Σ(Σ(b/\[i,j],Dx,i),Dx,j)
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
Composition
axiom
AB2 := A2 / B2; AB2::OutputForm = A2::OutputForm / B2::OutputForm
Type: Equation(OutputForm
?)
axiom
arity(AB2)::OutputForm = arity(A2)::OutputForm / arity(B2)::OutputForm
Type: Equation(OutputForm
?)
axiom
BA1 := B1 / A1; BA1::OutputForm = B1::OutputForm / A1::OutputForm
Type: Equation(OutputForm
?)
axiom
arity(BA1)::OutputForm = arity(B1)::OutputForm / arity(A1)::OutputForm
Type: Equation(OutputForm
?)
axiom
AB1 := A1 / B1; AB1::OutputForm = A1::OutputForm / B1::OutputForm
Type: Equation(OutputForm
?)
axiom
arity(AB1)::OutputForm = arity(A1)::OutputForm / arity(B1)::OutputForm
Type: Equation(OutputForm
?)
Powers
axiom
AB3:=(AB1*AB1)*AB1;
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(AB3)
Type: Prop(NonNegativeInteger
?)
axiom
test(AB3=AB1*(AB1*AB1))
Type: Boolean
axiom
test(AB3=AB1^3)
Type: Boolean
Sums
axiom
A12s := A1 + A2; A12s::OutputForm = A1::OutputForm + A2::OutputForm
Type: Equation(OutputForm
?)
axiom
arity(A12s)::OutputForm = arity(A1)::OutputForm + arity(A2)::OutputForm
Type: Equation(OutputForm
?)
axiom
B12s := B1 + B2; B12s::OutputForm = B1::OutputForm + B2::OutputForm
Type: Equation(OutputForm
?)
axiom
arity(B12s)::OutputForm = arity(B1)::OutputForm + arity(B2)::OutputForm
Type: Equation(OutputForm
?)
Multiplication
axiom
A3s:=(A1+A1)+A1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(A3s)
Type: Prop(NonNegativeInteger
?)
axiom
test(A3s=A1+(A1+A1))
Type: Boolean
axiom
test(A3s=A1*3)
Type: Boolean
axiom
B3s:=(B1+B1)+B1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(B3s)
Type: Prop(NonNegativeInteger
?)
axiom
test(B3s=B1+(B1+B1))
Type: Boolean
axiom
test(B3s=B1*3)
Type: Boolean
Product
axiom
AB11:=A1*B1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(AB11)
Type: Prop(NonNegativeInteger
?)
axiom
BA11:= B1*A1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(BA11)
Type: Prop(NonNegativeInteger
?)
axiom
AB := A*B
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(AB)
Type: Prop(NonNegativeInteger
?)
axiom
BA := B*A
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(BA)
Type: Prop(NonNegativeInteger
?)
axiom
X2:L:=inp[inp([script(x,[[i,j]]) for j in 1..2])$L for i in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
XB21:=X2*B1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(XB21)
Type: Prop(NonNegativeInteger
?)
axiom
Y2:L:=out[out([script(y,[[],[i,j]]) for j in 1..2])$L for i in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
XY22:=X2*Y2
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(XY22)
Type: Prop(NonNegativeInteger
?)
axiom
YX22:=Y2*X2
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(XY22)
Type: Prop(NonNegativeInteger
?)
axiom
test((A*A)*A=A*(A*A))
Type: Boolean
axiom
test((B*B)*B=B*(B*B))
Type: Boolean
axiom
test((A*B)*A=A*(B*A))
Type: Boolean
Multiple inputs and outputs
axiom
W:L:=out[inp[inp([script(w,[[i,j],[k]]) for j in 1..2])$L for i in 1..2] for k in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
WB1:=W*B1
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity(WB1)
Type: Prop(NonNegativeInteger
?)
Permutations and Identities
axiom
H:L:=[1,2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
X:L:=[2,1]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
test(X/X=H)
Type: Boolean
Tensor
axiom
tensor AB
Type: CartesianTensor
?(1,
2,
Fraction(Polynomial(Integer)))
Another kind of diagram:
___ _ _
___ _) = _\_ _
_/ ___ _)
axiom
Y:=out[inp[inp([script(y,[[i,j],[k]]) for k in 1..2])$L for j in 1..2] for i in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity Y
Type: Prop(NonNegativeInteger
?)
axiom
tensor Y
Type: CartesianTensor
?(1,
2,
Fraction(Polynomial(Integer)))
axiom
U:=inp[inp([script(u,[[i,j],[]]) for j in 1..2])$L for i in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity U
Type: Prop(NonNegativeInteger
?)
axiom
YU:=(Y*[1])/U
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity YU
Type: Prop(NonNegativeInteger
?)
axiom
UY:=([1]*Y)/U
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity UY
Type: Prop(NonNegativeInteger
?)
Handle
_/ _\__
axiom
λ:=inp[out[out([script(y,[[i],[j,k]]) for k in 1..2])$L for j in 1..2] for i in 1..2]
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity λ
Type: Prop(NonNegativeInteger
?)
axiom
tensor λ
Type: CartesianTensor
?(1,
2,
Fraction(Polynomial(Integer)))
axiom
Φ := λ/Y
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
axiom
arity Φ
Type: Prop(NonNegativeInteger
?)
Manipulations
axiom
ravel YU
Type: List(Fraction(Polynomial(Integer)))
axiom
test(unravel(arity YU,ravel YU)$L=YU)
Type: Boolean
axiom
map(x+->x+1,YU)$L
Type: LinearOperator
?(2,
OrderedVariableList
?([x,
y]),
Fraction(Polynomial(Integer)))
If linear operators really are to be morphisms (in the sense of category theory) then they must have a domain and a co-domain that are vector spaces, not just an in-degree and out-degree. E.g.:
Rep == Record(Dom:VectorSpace, Cod:VectorSpace, t:T)
But VectorSpace? is a category which would make Dom and Cod domains. The domains that currently satisfy VectorSpace? in Axiom are rather limited and seem oddly focused on number theory (finite fields). It is a good thing however that DirectProduct? is a conditional member of this cateogry.
axiom
DirectProduct(2,FRAC INT) has VectorSpace(FRAC INT)
Type: Boolean
Unfortunately:
axiom
DirectProduct(2,DirectProduct(2,FRAC INT)) has VectorSpace(FRAC INT)
Type: Boolean
The problem with VectorSpace? is that the domain [Vector]? is not a member of this category instead it satisfies VectoryCategory?.
Is it possible to treat tensors from CartesianTensor? as maps from VectorSpace? to VectorSpace?? We would like for example:
T:DirectProduct(dim,DirectProduct(dim,FRAC INT)) -> DirectProduct(dim,FRAC INT))
To be a linear operator with two inputs and one output.
A [FreeModule]
? over a [Field]
? is a VectorSpace
? unfortunately this is not currently understood by Axiom:
axiom
FreeModule(Fraction Integer,OrderedVariableList [e1,e1]) has VectorSpace(Fraction Integer)
Type: Boolean