, and the "Great Theorems" like the Open Mapping and Hahn-Banach theorems. SIAM Publications Library Nonlinear Functional Analysis

Functional analysis is learned through the fingers. Solving the exercises in Ciarlet’s or Kreyszig’s texts is non-negotiable. Conclusion

: Spaces with an inner product, allowing for geometric concepts like orthogonality and projections. Key Theorems Hahn-Banach Theorem