> x0:=0;y0:=1;

                               x0 := 0


                               y0 := 1

> ptseq:=[0,1];x:=x0;y:=y0;for k from 1 to 3 do
> y:=y+(.1)*(x-y);x:=x+0.1;ptseq:=ptseq,[x,y] od;pts:=[ptseq];

                           ptseq := [0, 1]


                                x := 0


                                y := 1


                               y := .9


                               x := .1


                      ptseq := [0, 1], [.1, .9]


                               y := .82


                               x := .2


                 ptseq := [0, 1], [.1, .9], [.2, .82]


                              y := .758


                               x := .3


           ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758]


           pts := [[0, 1], [.1, .9], [.2, .82], [.3, .758]]

> plot(pts);

> ptseq:=[0,1];x:=x0;y:=y0;for k from 1 to 20 do
> y:=y+(.1)*(x-y);x:=x+0.1;ptseq:=ptseq,[x,y] od;pts:=[ptseq];

                           ptseq := [0, 1]


                                x := 0


                                y := 1


                               y := .9


                               x := .1


                      ptseq := [0, 1], [.1, .9]


                               y := .82


                               x := .2


                 ptseq := [0, 1], [.1, .9], [.2, .82]


                              y := .758


                               x := .3


           ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758]


                              y := .7122


                               x := .4


    ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122]


                             y := .68098


                               x := .5


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098]


                             y := .662882


                               x := .6


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882]


                            y := .6565938


                               x := .7


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938]


                            y := .66093442


                               x := .8


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442]


                           y := .674840978


                               x := .9


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978]


                           y := .6973568802


                               x := 1.0


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802]


                           y := .7276211922


                               x := 1.1


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922]


                           y := .7648590730


                               x := 1.2


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730]


                           y := .8083731657


                               x := 1.3


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657]


                           y := .8575358491


                               x := 1.4


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491]


                           y := .9117822642


                               x := 1.5


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642]


                           y := .9706040378


                               x := 1.6


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378]


                           y := 1.033543634


                               x := 1.7


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378], [1.7, 1.033543634]


                           y := 1.100189271


                               x := 1.8


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378], [1.7, 1.033543634],

    [1.8, 1.100189271]


                           y := 1.170170344


                               x := 1.9


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378], [1.7, 1.033543634],

    [1.8, 1.100189271], [1.9, 1.170170344]


                           y := 1.243153310


                               x := 2.0


ptseq := [0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378], [1.7, 1.033543634],

    [1.8, 1.100189271], [1.9, 1.170170344], [2.0, 1.243153310]


pts := [[0, 1], [.1, .9], [.2, .82], [.3, .758], [.4, .7122],

    [.5, .68098], [.6, .662882], [.7, .6565938], [.8, .66093442],

    [.9, .674840978], [1.0, .6973568802], [1.1, .7276211922],

    [1.2, .7648590730], [1.3, .8083731657], [1.4, .8575358491],

    [1.5, .9117822642], [1.6, .9706040378], [1.7, 1.033543634],

    [1.8, 1.100189271], [1.9, 1.170170344], [2.0, 1.243153310]]

> plot(pts);

> with(DEtools);

[DEnormal, DEplot, DEplot3d, Dchangevar, PDEchangecoords, PDEplot,

    autonomous, convertAlg, convertsys, dfieldplot, indicialeq,

    phaseportrait, reduceOrder, regularsp, translate, untranslate,

    varparam]

> DEplot(diff(y(x),x)=x-y,y(x),x=0..2,y=0..2);
Error, wrong number (or type) of parameters in function diff
> x:='x';y:='y';

                                x := x


                                y := y

> DEplot(diff(y(x),x)=x-y,y(x),x=0..2,y=0..2);

>