I have a system of nonlinear algebraic equations which I'm wanting to solve numerically (for example with a Newton iteration based technique). I can formulate this either as the single system of size N:

**f**( **x** ) = **0**

or as the nested systems of size P, Q:

**g**( **y**, **z**) = **0**,

**h**( **z** ) = **0**.

It may be that P+Q < N (ie, the nested problem reduces the size of my system to solve).

Is it known which approach is more computationally efficient?