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S-procedure

The S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality.

Version
v1 · 2026-09-28 · History
Domain-specific #
11865
Domain group
Formal Sciences
Origin domain
Mathematics
Subdomains
Control Theory, Convex Optimization, Quadratic Inequalities → Mathematics

Core Idea

S-procedure is treated here as the recurring control theory identity summarized by this source-grounded definition: The S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality. The S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality. The S-procedure was developed independently in a number of different contexts and has applications in control theory, linear algebra and mathematical optimization.

Scope of Application

  • Documented setting. The S-procedure was developed independently in a number of different contexts and has applications in control theory, linear algebra and mathematical optimization.

  • Statement of the S-procedure. Let F 1 and F 2 be symmetric matrices, g 1 and g 2 be vectors and h 1 and h 2 be real numbers.

  • Statement of the S-procedure. Assume that there is some x 0 such that the strict inequality x0^T F1 x0 + 2g1^T x0 + h1 holds.

  • Statement of the S-procedure. x^T F1 x + 2g1^T x + h1 \le 0 \Longrightarrow x^T F2 x + 2g2^T x + h2 \le 0.

  • Statement of the S-procedure. holds if and only if there exists some nonnegative number λ such that.

Clarity

A clear use of S-procedure names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is The S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality.

Manages Complexity

S-procedure compresses multiple control theory details into a stable diagnostic relation. The source shows both the central mechanism—assume that there is some x 0 such that the strict inequality x0^T F1 x0 + 2g1^T x0 + h1 holds.—and the practical consequence—the S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality.

Abstract Reasoning

  1. Type the carrier. Identify the control theory entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: The S-procedure or S-lemma is a mathematical result that gives conditions under which a particular quadratic inequality is a consequence of another quadratic inequality.
  3. Check operation and conditions. x^T F1 x + 2g1^T x + h1 \le 0 \Longrightarrow x^T F2 x + 2g2^T x + h2 \le 0. 4.

Knowledge Transfer

Within the home domain. Knowledge about S-procedure transfers literally when a new case preserves the same carrier type, relation, and recognition test. The S-procedure was developed independently in a number of different contexts and has applications in control theory, linear algebra and mathematical optimization. Let F 1 and F 2 be symmetric matrices, g 1 and g 2 be vectors and h 1 and h 2 be real numbers. Beyond the home domain. No canonical parent is asserted for S-procedure.

Neighborhood in Abstraction Space

S-procedure sits in a crowded region of the domain-specific corpus (19th percentile for distinctiveness): several abstractions share nearly its structure, so a description that fits it tends to fit its neighbors too.

Family — Unclustered & Miscellaneous (2551 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08