function Feb6()
format short
n = 4;
A = randn(n,n);
b = randn(n,1);
[L,U,P] = lu(A);
[L,U,piv] = lu(A,'vector');
P = P
piv = piv
% Solve Ax = b...
y = L\b(piv); x = U\y;
PartaConfirm = [ A\b  x]
% Solve A'x = (P'LU)'x = U'L'Px = b;
w = U'\b;
z = L'\w;
x(piv) = z   % x = P'z
PartbConfirm = [ A'\b  x]