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arXiv · 2512.05878

Complex Bounded Operators in Isabelle/HOL

Dominique Unruh·José Manuel Rodríguez Caballero
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Abstract

We present a formalization of bounded operators on complex vector spaces in Isabelle/HOL. Our formalization contains material on complex vector spaces (normed spaces, Banach spaces, Hilbert spaces) that complements and goes beyond the developments of real vectors spaces in the Isabelle/HOL standard library. We define the type of bounded operators between complex vector spaces (cblinfun) and develop the theory of unitaries, projectors, extension of bounded linear functions (BLT theorem), adjoints, Loewner order, closed subspaces and more. For the finite-dimensional case, we provide code generation support by identifying finite-dimensional operators with matrices as formalized in the Jordan_Normal_Form AFP entry.

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Dominique Unruh, José Manuel Rodríguez Caballero. 2025-12-05. Complex Bounded Operators in Isabelle/HOL. https://doi.org/10.4230/lipics.itp.2026.3

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