[Axiom-developer] [#180 bug #9216 differentiating sums with respect to a bound is wrong] (new) bug #9216 differentiating sums with respect to a bound is wrong

[Bill Page]

Changes 
http://page.axiom-developer.org/zope/mathaction/180Bug9216DifferentiatingSumsWithRespectToABoundIsWrong/diff
--

--removed:
-

++added:
Compile and Test

  SPAD files for the functional world should be compiled in the
  following order::

    op  kl  function  funcpkgs  manip  algfunc
    elemntry  constant  funceval  COMBFUNC  fe

<pre>!\begin{axiom}
)abbrev category COMBOPC CombinatorialOpsCategory
++ Category for summations and products
++ Author: Manuel Bronstein
++ Date Created: ???
++ Date Last Updated: 22 February 1993 (JHD/BMT)
++ Description:
++   CombinatorialOpsCategory is the category obtaining by adjoining
++   summations and products to the usual combinatorial operations;
CombinatorialOpsCategory(): Category ==
  CombinatorialFunctionCategory with
    factorials : $ -> $
      ++ factorials(f) rewrites the permutations and binomials in f
      ++ in terms of factorials;
    factorials : ($, Symbol) -> $
      ++ factorials(f, x) rewrites the permutations and binomials in f
      ++ involving x in terms of factorials;
    summation  : ($, Symbol)            -> $
      ++ summation(f(n), n) returns the formal sum S(n) which verifies
      ++ S(n+1) - S(n) = f(n);
    summation  : ($, SegmentBinding $)  -> $
      ++ summation(f(n), n = a..b) returns f(a) + ... + f(b) as a
      ++ formal sum;
    product    : ($, Symbol)            -> $
      ++ product(f(n), n) returns the formal product P(n) which verifies
      ++ P(n+1)/P(n) = f(n);
    product    : ($, SegmentBinding  $) -> $
      ++ product(f(n), n = a..b) returns f(a) * ... * f(b) as a
      ++ formal product;

)abbrev package COMBF CombinatorialFunction
++ Provides the usual combinatorial functions
++ Author: Manuel Bronstein
++ Date Created: 2 Aug 1988
++ Date Last Updated: 14 December 1994
++ Description:
++   Provides combinatorial functions over an integral domain.
++ Keywords: combinatorial, function, factorial.
++ Examples:  )r COMBF INPUT



CombinatorialFunction(R, F): Exports == Implementation where
  R: Join(OrderedSet, IntegralDomain)
  F: FunctionSpace R

  OP  ==> BasicOperator
  K   ==> Kernel F
  SE  ==> Symbol
  O   ==> OutputForm
  SMP ==> SparseMultivariatePolynomial(R, K)
  Z   ==> Integer

  POWER       ==> "%power"::Symbol
  OPEXP       ==> "exp"::Symbol
  SPECIALDIFF ==> "%specialDiff"
  SPECIALDISP ==> "%specialDisp"

  Exports ==> with
    belong?    : OP -> Boolean
      ++ belong?(op) is true if op is a combinatorial operator;
    operator   : OP -> OP
      ++ operator(op) returns a copy of op with the domain-dependent
      ++ properties appropriate for F;
      ++ error if op is not a combinatorial operator;
    "**"       : (F, F) -> F
      ++ a ** b is the formal exponential a**b;
    binomial   : (F, F) -> F
      ++ binomial(n, r) returns the number of subsets of r objects
      ++ taken among n objects, i.e. n!/(r! * (n-r)!);
    permutation: (F, F) -> F
      ++ permutation(n, r) returns the number of permutations of
      ++ n objects taken r at a time, i.e. n!/(n-r)!;
    factorial  : F -> F
      ++ factorial(n) returns the factorial of n, i.e. n!;
    factorials : F -> F
      ++ factorials(f) rewrites the permutations and binomials in f
      ++ in terms of factorials;
    factorials : (F, SE) -> F
      ++ factorials(f, x) rewrites the permutations and binomials in f
      ++ involving x in terms of factorials;
    summation  : (F, SE) -> F
      ++ summation(f(n), n) returns the formal sum S(n) which verifies
      ++ S(n+1) - S(n) = f(n);
    summation  : (F, SegmentBinding F)  -> F
      ++ summation(f(n), n = a..b) returns f(a) + ... + f(b) as a
      ++ formal sum;
    product    : (F, SE) -> F
      ++ product(f(n), n) returns the formal product P(n) which verifies
      ++ P(n+1)/P(n) = f(n);
    product    : (F, SegmentBinding  F) -> F
      ++ product(f(n), n = a..b) returns f(a) * ... * f(b) as a
      ++ formal product;
    iifact     : F -> F
      ++ iifact(x) should be local but conditional;
    iibinom    : List F -> F
      ++ iibinom(l) should be local but conditional;
    iiperm     : List F -> F
      ++ iiperm(l) should be local but conditional;
    iipow      : List F -> F
      ++ iipow(l) should be local but conditional;
    iidsum     : List F -> F
      ++ iidsum(l) should be local but conditional;
    iidprod    : List F -> F
      ++ iidprod(l) should be local but conditional;
    ipow       : List F -> F
      ++ ipow(l) should be local but conditional;

  Implementation ==> add
    ifact     : F -> F
    iiipow    : List F -> F
    iperm     : List F -> F
    ibinom    : List F -> F
    isum      : List F -> F
    idsum     : List F -> F
    iprod     : List F -> F
    idprod    : List F -> F
    ddsum     : List F -> O
    ddprod    : List F -> O
    ddiff     : List F -> O
    fourth    : List F -> F
    dvpow1    : List F -> F
    dvpow2    : List F -> F
    summand   : List F -> F
    dvsum     : (List F, SE) -> F
    dvdsum    : (List F, SE) -> F
    facts     : (F, List SE) -> F
    K2fact    : (K, List SE) -> F
    smpfact   : (SMP, List SE) -> F

    dummy == new()$SE :: F
-- this works if we don't accidently use such a symbol as a bound of summation
-- or product 
    opfact  := operator("factorial"::Symbol)$CommonOperators
    opperm  := operator("permutation"::Symbol)$CommonOperators
    opbinom := operator("binomial"::Symbol)$CommonOperators
    opsum   := operator("summation"::Symbol)$CommonOperators
    opdsum  := operator("%defsum"::Symbol)$CommonOperators
    opprod  := operator("product"::Symbol)$CommonOperators
    opdprod := operator("%defprod"::Symbol)$CommonOperators
    oppow   := operator(POWER::Symbol)$CommonOperators
    opdiff  := operator("%diff"::Symbol)$CommonOperators


    factorial x          == opfact x
    binomial(x, y)       == opbinom [x, y]
    permutation(x, y)    == opperm [x, y]

    import F
    import Kernel F

    number?(x:F):Boolean ==
      if R has RetractableTo(Z) then
        ground?(x) or
         ((retractIfCan(x)@Union(Fraction(Z),"failed")) case Fraction(Z))
      else
        ground?(x)

    x ** y               == 
      -- Do some basic simplifications
      is?(x,POWER) =>
        args : List F := argument first kernels x
        not(#args = 2) => error "Too many arguments to **"
        number?(first args) and number?(y) =>
          oppow [first(args)**y, second args]
        oppow [first args, (second args)* y]
      -- Generic case
      exp : Union(Record(val:F,exponent:Z),"failed") := isPower x
      exp case Record(val:F,exponent:Z) =>
        expr := exp::Record(val:F,exponent:Z)
        oppow [expr.val, (expr.exponent)*y]
      oppow [x, y]

    belong? op           == has?(op, "comb")
    fourth l             == third rest l
    dvpow1 l             == second(l) * first(l) ** (second l - 1)
    factorials x         == facts(x, variables x)
    factorials(x, v)     == facts(x, [v])
    facts(x, l)          == smpfact(numer x, l) / smpfact(denom x, l)
    summand l            == eval(first l, retract(second l)@K, third l)

    product(x:F, i:SE) ==
      dm := dummy
      opprod [eval(x, k := kernel(i)$K, dm), dm, k::F]

    summation(x:F, i:SE) ==
      dm := dummy
      opsum [eval(x, k := kernel(i)$K, dm), dm, k::F]

    dvsum(l, x) ==
      k  := retract(second l)@K
[456 more lines...]

--
forwarded from http://page.axiom-developer.org/zope/mathaction/address@hidden