  In this paper, we present a two phase method for solving nonlinear
programming problems called Nonlinear Polyhedral Active Set Algorithm (NPASA)
that has global and local convergence guarantees under reasonable assumptions.
The first phase consists of an augmented Lagrangian method to ensure global
convergence while the second phase is designed to promote fast local
convergence by performing a balanced reduction of two error estimators for
nonlinear programs. After presenting error estimators for nonlinear programs
and our algorithm NPASA, we establish global convergence properties for NPASA.
Local quadratic convergence of NPASA is established in a companion paper.
