constant N = 15, M=3
sequence x = {1.47,1.50,1.52,1.55,1.57,
              1.60,1.63,1.65,1.68,1.70,
              1.73,1.75,1.78,1.80,1.83},
         y = {52.21,53.12,54.48,55.84,57.20,
              58.57,59.93,61.29,63.11,64.47,
              66.28,68.10,69.92,72.19,74.46},
         s = repeat(0,N),
         t = repeat(0,N),
         a = repeat(repeat(0,M+1),M)

    for k=1 to 2*M do
        for i=1 to N do
            s[k] += power(x[i],k-1)
            if k<=M then t[k] += y[i]*power(x[i],k-1) end if
        end for
    end for

    -- build linear system

    for row=1 to M do
        for col=1 to M do
            a[row,col] = s[row+col-1]
        end for
        a[row,M+1] = t[row]
    end for

    puts(1,"Linear system coefficents:\n")
    pp(a,{pp_Nest,1,pp_IntFmt,"%7.1f",pp_FltFmt,"%7.1f"})

    for j=1 to M do
        integer i = j
        while a[i,j]=0 do i += 1 end while
        if i=M+1 then
            ?"SINGULAR MATRIX !"
            ?9/0
        end if
        for k=1 to M+1 do
            {a[j,k],a[i,k]} = {a[i,k],a[j,k]}
        end for
        atom Y = 1/a[j,j]
        a[j] = sq_mul(a[j],Y)
        for i=1 to M do
            if i<>j then
                Y=-a[i,j]
                for k=1 to M+1 do
                    a[i,k] += Y*a[j,k]
                end for
            end if
        end for
    end for

    puts(1,"Solutions:\n")
    ?columnize(a,M+1)[1]