{\it Elements of Operatory Theory} is largely self-contained and geared towards graduate students, mathematicians and scientists who need to apply operator theory to their field. Written in a user- friendly, motivating style, fundamental topics are presented systematically, i.e, set theory, algebraic structures, topological structures, Banach spaces, Hilbert Spaces, culminating with the Spectral Theorem. The exposition is concept-driven and avoids the formula-computational approach. Key features * presents required background material to each chapter * offers 300 rigorous proofs * more than 100 examples and interesting counterexamples * over 300 problems, many with hints. Excellent text for the classroom and aweiterlesen