#noindex
##===리듀스,Reduce =,Reduce 리듀스 Reduce
http://www.reduce-algebra.com/

[[computer_algebra_system]], [[Portable_Standard_Lisp,PSL]]로 씌어짐.
상용이었으나 2008년 무료화 및 오픈소스 공개. BSD_license.
By https://en.wikipedia.org/wiki/Anthony_C._Hearn

[[행렬,matrix]] : `mat()`
[[리스트,list]] : `{...}` empty_list : `{}`
 via manual ch4 lists

tmp from https://cafe.naver.com/kpope/1354
{
편미분하기
df(x^2 + y^2 + z^2, x);
2*x

df is the REDUCE operator to compute the derivative. In `df(f,x),` the operator df is to compute
the partial derivative of f with respect to b. Note that the x dependence of f should be declared in adavance.
If it is not the case, then REDUCE assumes that f is independent of x and gives 0. 
​

The application of nested df operators realizes the computation of multiple derivatives.
`df(df(f,x),y)` computes
the second-order derivative $\frac{\partial^2 f}{\partial y\partial x}.$
​

`depend x,v,t;`
states that x is a function of v and t. This is to declare the implicit dependence of variables.
Because of this declaration,
`df(x^2,t)` is not 0 but $2x\frac{dx}{dt}.$ Here, df(x,t) is not explicitly computed but the evaluation is delayed.
​

If you understand what the following is, then I hope you to explain what it is below!
Note that `df(x,t,2)=` $\frac{d^2x}{dt^2}$ is the second-order time derivative of x.
}



Up: [[computer_algebra_system]]

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Twins:
[[WpKo:리듀스_(컴퓨터_대수학_시스템)]]
= https://ko.wikipedia.org/wiki/리듀스_(컴퓨터_대수학_시스템)
[[WpEn:Reduce_(computer_algebra_system)]]
= https://en.wikipedia.org/wiki/Reduce_(computer_algebra_system)