Edit detail for SandBoxSymbolic revision 10 of 35

axiom
a:Union(Symbol,Integer)

axiom
b:Union(Symbol,Integer)

axiom
c:=a*3-b*2

axiom
p:UP(x,Integer):=x*2-7

axiom
pc := p c

axiom
f(x)==x^3-x^2+1

axiom
fb := f b

Compiling function f with type Symbol -> Polynomial Integer

axiom
a:=1

axiom
b:=-3

axiom
eval(pc,['a=a,'b=b])

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eval(c,['a=a,'b=b])

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eval(fb,['a=a,'b=b])

axiom
a:=3.14
   Cannot convert right-hand side of assignment
   3.14
      to an object of the type Union(Symbol,Integer) of the left-hand 
      side.

spad
)abbrev domain INDET Indeterminant
++ Description:
++   Based on InputForm
Indeterminant():
  Join(SExpressionCategory(String,Symbol,Integer,DoubleFloat,OutputForm),
       ConvertibleTo SExpression) with
    eval: % -> Any
      ++ eval(f) passes f to the interpreter.
    binary   : (%, List %) -> %
      ++ \spad{binary(op, [a1,...,an])} returns the input form
      ++ corresponding to  \spad{a1 op a2 op ... op an}.
    function : (%, List Symbol, Symbol) -> %
      ++ \spad{function(code, [x1,...,xn], f)} returns the input form
      ++ corresponding to \spad{f(x1,...,xn) == code}.
    lambda   : (%, List Symbol) -> %
      ++ \spad{lambda(code, [x1,...,xn])} returns the input form
      ++ corresponding to \spad{(x1,...,xn) +-> code} if \spad{n > 1},
      ++ or to \spad{x1 +-> code} if \spad{n = 1}.
    "+"      : (%, %) -> %
      ++ \spad{a + b} returns the input form corresponding to \spad{a + b}.
    "-"      : (%, %) -> %
      ++ \spad{a - b} returns the input form corresponding to \spad{a - b}.
    "-"      : % -> %
      ++ \spad{-a} returns the input form corresponding to \spad{-a}.
    "*"      : (%, %) -> %
      ++ \spad{a * b} returns the input form corresponding to \spad{a * b}.
    "/"      : (%, %) -> %
      ++ \spad{a / b} returns the input form corresponding to \spad{a / b}.
    "**"     : (%, NonNegativeInteger) -> %
      ++ \spad{a ** b} returns the input form corresponding to \spad{a ** b}.
    "**"     : (%, Integer) -> %
      ++ \spad{a ** b} returns the input form corresponding to \spad{a ** b}.
    unparse  : % -> String
      ++ unparse(f) returns a string s such that the parser
      ++ would transform s to f.
      ++ Error: if f is not the parsed form of a string.
    declare  : List %   -> Symbol
      ++ declare(t) returns a name f such that f has been
      ++ declared to the interpreter to be of type t, but has
      ++ not been assigned a value yet.
      ++ Note: t should be created as \spad{devaluate(T)$Lisp} where T is the
      ++ actual type of f (this hack is required for the case where
      ++ T is a mapping type).
    compile  : (Symbol, List %) -> Symbol
      ++ \spad{compile(f, [t1,...,tn])} forces the interpreter to compile
      ++ the function f with signature \spad{(t1,...,tn) -> ?}.
      ++ returns the symbol f if successful.
      ++ Error: if f was not defined beforehand in the interpreter,
      ++ or if the ti's are not valid types, or if the compiler fails.
    coerce : Integer -> %
 == SExpression add
    Rep := SExpression
    mkProperOp: Symbol -> %
    strsym    : % -> String
    tuplify   : List Symbol -> %
    coerce(x:Integer):% == convert(x)
    coerce(x:%):OutputForm == expr x
    convert(x:%):SExpression == x pretend SExpression
    conv(ll : List %): % ==
      convert(ll pretend List SExpression)$SExpression pretend %
    lambda(f,l) == conv([convert(+->),tuplify l,f]$List(%))
    eval x ==
      v := interpret(x)$Lisp
      mkObj(unwrap(objVal(v)$Lisp)$Lisp, objMode(v)$Lisp)$Lisp
    convert(x:DoubleFloat):% ==
      convert(x)$Rep
    strsym s ==
      string? s => string s
      symbol? s => string symbol s
      error "strsym: form is neither a string or symbol"
    unparse x ==
      atom?(s:% := form2String(x)$Lisp) => strsym s
      concat [strsym a for a in destruct s]
    declare signature ==
      declare(name := new()$Symbol, signature)$Lisp
      name
    compile(name, types) ==
      symbol car cdr car
        selectLocalMms(mkProperOp name, convert(name)@%,
          types, nil$List(%))$Lisp
    mkProperOp name ==
      op := mkAtree(nme := convert(name)@%)$Lisp
      transferPropsToNode(nme, op)$Lisp
      convert op
    binary(op, args) ==
      (n := #args) < 2 => error "Need at least 2 arguments"
      n = 2 => convert([op, first args, last args]$List(%))
      convert([op, first args, binary(op, rest args)]$List(%))
    tuplify l ==
      empty? rest l => convert first l
      conv
        concat(convert(Tuple), [convert x for x in l]$List(%))
    function(f, l, name) ==
      nn := convert(new(1 + #l, convert(nil()$List(%)))$List(%))@%
      conv([convert(DEF), conv(cons(convert(name)@%,
                        [convert(x)@% for x in l])), nn, nn, f]$List(%))
    s1 + s2 ==
      conv [convert(+), s1, s2]$List(%)
    s1 - s2 ==
      conv [convert(-), s1, s2]$List(%)
    _-(s1) ==
      conv [convert(-), s1]$List(%)
    s1 * s2 ==
      conv [convert(*), s1, s2]$List(%)
    s1:% ** n:Integer ==
      conv [convert(**), s1, convert n]$List(%)
    s1:% ** n:NonNegativeInteger == s1 ** (n::Integer)
    s1 / s2 ==
      conv [convert(/), s1, s2]$List(%)

axiom
)clear all
   All user variables and function definitions have been cleared.

axiom
m:Union(Indeterminant,Matrix Integer)

axiom
n:Union(Indeterminant,Matrix Integer)

axiom
a:Union(Indeterminant,Integer)

axiom
b:Union(Indeterminant,Integer)

axiom
ab:=(3*a+b)*(a-2*b)

axiom
a:Integer:=1  -- because 0 and 1 can be symbolic!

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eval ab

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b:Integer:=0

axiom
a:=-10

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eval ab

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mn1:= m*n-n*m

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mn2:=(m+n)*(m-n-1)

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m:=matrix [[1,2],[3,4]]

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n:=matrix [[-1,-2],[-3,4]]

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eval mn1

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eval mn2