Code in "Newton method in 2D" doesn't match the latex equation

[goalaleo]

In section 1.6 on newton method, in the 2D implementation the julia code doesn't match the latex equations.
The new approximation is defined to be x1 = x0 + δ, but in the julia function it's written as return x0 - δ.
This works in the code because in the definition of δthe minus sign is also missing, so practically it doesn't matter (they cancel out). However, I think it would be more intuitive if the code matched the latex equations