#LAPLACE
#USEFLOAT=FALSE
#USEERROR=FALSE
#SIMPLIFY=TRUE
#ERRBND=15
#EXPDSP=5
#PREC=8
#F1=f(x)=
#F2=g(x)=
#F3=h(x)=f(x)/g(x)
#F4=matrix(
#F5=vector(
#F6=diff(f)
#F7=diff(g)
#F8=diff(h)
#F9=taylor(f,0)
#F10=taylor(f,1)
#F11=%(run type s:startup-sequence)
#F12=
#F13=
#F14=
#F15=
#F16=
#F17=
#F18=
#F19=
#F20=
m1=[1,2,-1,0;2,3,-2,2;-2,-4,0,5;0,1,2,3]
m1b=invert(m1)
m2=[2,-1,0,0;-1,2,-1,0;0,-1,2,-1;0,0,-1,2]
const(a,b,c,d)
m3=[0,-a,-b;a,0,-c;b,c,0]
m=swaprows(m3,1,2)
m=multrow(m,1,-inv(a))
m=addrows(m,3,1,b)
m=multrow(m,2,inv(a))
m=addrows(m, 3, 2, c)

solve(m3)
m4=[1,0,1,0;0,a,0,b;a,0,0,1;0,1,-b,0]
det(m1)
det(m2)
det(m3)
det(m4)
m5=[a,-b,-c,-d;b,a,d,-c;c,-d,a,b;d,c,-b,a]
d5=det(m5)
rank(m1)
solve(m1)
rank(m2)
solve(m2)
rank(m3)
solve(m3)
rank(m4)
solve(m4)
z1=[1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,1,0,0,0,0,0;0,0,1,0,0,0,0;0,0,0,1,0,0,0;0,0,0,0,1,0,0;0,0,0,0,0,1,0;0,0,0,0,0,0,1]
z2=[1,0,0,0,0,0,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,0,1,0,0,0,0;0,0,0,1,0,0,0;0,0,0,0,1,0,0;0,0,0,0,0,1,0;0,0,0,0,0,0,1]
z3=[1,0,0,0,0,0,0;0,1,0,0,0,0,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,0,0,1,0,0,0;0,0,0,0,1,0,0;0,0,0,0,0,1,0;0,0,0,0,0,0,1]
z4=[1,0,0,0,0,0,0;0,1,0,0,0,0,0;0,0,1,0,0,0,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,0,0,0,1,0,0;0,0,0,0,0,1,0;0,0,0,0,0,0,1]
z5=[1,0,0,0,0,0,0;0,1,0,0,0,0,0;0,0,1,0,0,0,0;0,0,0,1,0,0,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,0,0,0,0,1,0;0,0,0,0,0,0,1]
z6=[1,0,0,0,0,0,0;0,1,0,0,0,0,0;0,0,1,0,0,0,0;0,0,0,1,0,0,0;0,0,0,0,1,0,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7;0,0,0,0,0,0,1]
z7=[1,0,0,0,0,0,0;0,1,0,0,0,0,0;0,0,1,0,0,0,0;0,0,0,1,0,0,0;0,0,0,0,1,0,0;0,0,0,0,0,1,0;1/7,1/7,1/7,1/7,1/7,1/7,1/7]
z_1=z7*z6*z5*z4*z3*z2*z1
z_2=inv(z_1)
z_2*[1,1,1,1,1,1,1]
z_2*[7,6,5,4,3,2,1]
z_3=combine(z_2-umatrix(7), [0,0,0,0,0,0,1])
z_4=solve(z_3)
z_4*[0,0,0,0,0,0,1,0]