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Table of Contents

Public units

UnitTitleUse
ReadmeMathematical Thinking - ReadmeFollow connected mathematical work.
PrefaceMathematical Thinking - PrefaceUnderstand the connected methods, their rationale, sources and limits.

Part A - Choose and relate constructions

§ID & TitleStatusKeywords & Search QueriesDependencies
1MATH.16 - Choose a Mathematical Construction from Its Required Maps (Universal Property)Usable, evolvinguniversal property; product; coproduct; pullback; function object; currying. What maps should a new object support, and how can that requirement select a construction?MATH.2 for quotients; MATH.5 for generator extensions; MATH.7 for reversible representations; C.29 for interpretation in another subject.
2MATH.17 - Construct Mathematical Spaces of Operations and Operations on ThemUsable, evolvingoperations as objects; admissible functions; closure; higher-order operation; transformation law. How can a rule be constructed, combined or changed while retaining the consequence its use needs?MATH.16 for function objects; MATH.1/.2 for retained steps or identification; MATH.18 for interpretation between accounts; C.29 for a working-method application.
3MATH.1 - Build a Mathematical Structure of Composable PathsUsable, evolvinggenerators; paths; endpoints; identity; associativity. Which elementary steps can be composed? When do different sequences need to remain distinct?MATH.2 when paths will be identified; C.29 when the construction represents another subject.
4MATH.2 - Treat Objects as the Same While Preserving Operations (Quotient)Usable, evolvingquotient; congruence; equivalence; partial operation; refinement. Can these objects be treated as the same without losing a later operation or result?MATH.1 when paths first need construction; MATH.6 for a counterexample to the proposed identification.
5MATH.5 - Extend a Generator Assignment While Preserving Operations (Homomorphism)Usable, evolvinggenerators; relations; homomorphism; free structure; extension. How can a choice on generators determine an operation-preserving map on everything they generate?MATH.1 for paths; MATH.2 when an extension must descend to a quotient.
6MATH.7 - Transport a Mathematical Structure Through a BijectionUsable, evolvingbijection; transport; inverse map; isomorphism; domain of operation. How can a useful operation, law and answer be carried through a change of representation?MATH.2 when identification is proposed instead of a bijection; C.29 for interpretation in another subject.
7MATH.18 - Compare Mathematical Accounts through InterpretationsUsable, evolvinginterpretation; primitive operation; preservation; reflection; round trip; equivalence. Which constructions, equations and maps transfer between two mathematical descriptions, and what can be recovered?MATH.5 for generated interpretations; MATH.7 for bijective transport; MATH.2 for quotients; MATH.17 for transformations of operations.

Part B - Construct and criticize arguments

§ID & TitleStatusKeywords & Search QueriesDependencies
1MATH.19 - Construct a Proof through Intermediate ClaimsStablelemma; backward and forward reasoning; generalization; proof dependency. Which intermediate claim connects the available premises to the desired conclusion?B.5.RA for recovery of a supplied argument; MATH.4 for induction; MATH.6 for a separating case; MATH.12 for obtaining an object from the proof.
2MATH.4 - Construct a Witness by InductionUsable, evolvinginduction; recursive witness; base and step; representation. How can a proof supply an object for every finite input? Does the construction respect equivalent representations?MATH.2 when a recursive construction must respect identification; MATH.12 for extracting constructions from other proof rules.
3MATH.12 - Extract a Construction from a ProofUsable, evolvingconstructive proof; witness; function; pair; branch; finite search; computation. Which data-producing operation does a proof supply, and what is needed to execute it?B.5.RA for an unfamiliar argument; MATH.4 for induction; C.29.2/.3 for formulation or execution questions.
4MATH.6 - Refute a Mathematical Claim with a CountermodelUsable, evolvingcounterexample; countermodel; quantifiers; finite scope; encoding. What concrete structure refutes the claim? What does an unsuccessful bounded search leave unresolved?B.5.RA if the claim’s argument needs recovery; MATH.2 when the counterexample defeats an identification.
5MATH.20 - Bound a Mathematical Unknown by Comparable ConstructionsStablebound; inequality; enclosure; relaxation; attainability; residual and error. Which comparison can answer the question before the whole unknown is obtained?MATH.19 for an intermediate inequality; MATH.6 for a failed bound; MATH.21 for convergent approximation; FPF for choosing further work.

Part C - Change a construction and develop its theory

§ID & TitleStatusKeywords & Search QueriesDependencies
1MATH.11 - Construct an Invariant from Transformation RulesUsable, evolvinginvariant; transformation rule; preservation equation; coefficient; reachability. How can a preserved expression be constructed and used to obtain a formula or exclude a target?MATH.2 for identification; MATH.7 for transport; C.29 for a consequence about the modeled subject.
2MATH.13 - Derive a Consequence from a SymmetryUsable, evolvingsymmetry; uniqueness; fixed point; orbit; conservation; numerical update. What does a transformation preserve, and which conclusion actually follows from that symmetry?MATH.8 for the full orbit construction; MATH.9 for compatible choice; MATH.10 for admissible variation.
3MATH.8 - Generate a Solution Family by SymmetryUsable, evolvinggroup action; solution orbit; stabilizer; repetitions; representatives. Which solutions can be generated from one solution, and how much of the solution set does this cover?MATH.13 for an unresolved symmetry consequence; MATH.9 when one compatible representative is required.
4MATH.9 - Determine Whether and How a Choice Rule Can Respect SymmetryUsable, evolvingequivariant choice; stabilizer; symmetry obstruction; additional data. Can one allowed answer be chosen consistently with symmetry? What can replace an impossible choice?MATH.8 for solution orbits; MATH.13 for an earlier consequence or uniqueness question.
5MATH.10 - Improve a Mathematical Candidate or Derive a Necessary Condition by Admissible VariationUsable, evolvingadmissible variation; improving change; stationary point; boundary minimum; constraint; first variation. Which change is allowed, can it improve the candidate, and what condition follows? Does that condition establish an optimum?B.5.RA if the variational argument needs recovery; C.29 when a mathematical variation represents a subject change.
6MATH.21 - Construct an Object through Convergent ApproximationsStablelimit; completeness; compatible approximation; uniform convergence; error control. How can finite approximations construct an object while retaining the next operation?MATH.20 for bounds; MATH.19 for convergence and interchange arguments; MATH.2 for classes of representations; computational methods for effective obtaining.
7MATH.22 - Change Axioms and Trace Their ConsequencesStableaxiom change; theory; interpretation; model; independence; proof repair. Which constructions and consequences survive when assumptions change?MATH.18 for interpretations; MATH.19 for replacement proofs; MATH.6 for countermodels; MATH.23 for a further conjecture.
8MATH.23 - Develop a Conjecture by Changing a ConstructionStableconjecture; construction variation; proof and refutation; generalization; next problem. How can a change or obstruction yield a precise useful claim and an attainable next operation?MATH.19 for proof construction; MATH.6 for refutation; MATH.22 for theory change; B.5.QD/C.40.CD for continued inquiry.