Keep the whole promise.
A final readiness band hides gaps during construction. The model carries the readiness curve as well as the endpoint.
START WITH A COUNTEREXAMPLE
Can this design be delivered?
Choose a case, then change the constraints. Every retained option includes a construction path.
Here, readiness means the lowest available band across passage, guide fencing and monitoring. These fictional management bands do not measure animal use or ecological benefit.
CALCULATED RESULT
Calculating…
THE RESOURCE ANTICHAIN
Different ways to meet the same brief
Less cost, earlier completion, fewer access units: each retained point has a trade-off. Select one to inspect its path.
FROM CHOICE TO CONSTRUCTION
Walk the selected path
Filled bars: readiness during work. Dark line: commissioned readiness at slot end. Dashed line: required readiness floor.
Read the full construction trace
| Slot | Work | Readiness during work | Commissioned bands after work | Cost | Access |
|---|
Compose before reducing.
Guide-fence readiness, monitoring continuity, crews and access restrict the set of admissible paths. Temporary works earn their place through this interface.
Retain the alternatives.
Only then reduce resource tuples to their Pareto antichain. An empty frontier is a result about this finite catalogue and this brief.
Experiment receipt
Reload this URL to reopen the brief. Path selection and replay are temporary. Export creates a local JSON file; no works or commitments are authorised.
END → WAY → CONSTRUCTION
A path can be an implementation.
The advance is to change what a design choice contains. The finished system alone is too small an object for the staged-delivery question.
Implementation set IAll legal finite action histories
→Functionality exec(i)Readiness-during-work curve + commissioned-readiness curve
+Resources eval(i)Cost, finish slot, peak access
What this wildlife foray asks
Use monotone co-design to tackle a corridor upgrade without avoiding the difficult part: aligning passage, guide fencing and monitoring across staged delivery constraints. A passage tier needs matching guide fencing already commissioned. Explain the resulting paths and trade-offs at project-director level.
What is constructed here
For each path, commissioned permanent tiers only increase. A separate readiness measure records what is available during each work slot. Installing a larger crossing does not by itself guarantee that every required module remains ready. This app queries a constant readiness floor and one end-of-slot commissioning requirement, and solves again for every new brief.
The engine composes a finite action catalogue with guide-fence prerequisites, monitoring continuity and shared crew/access limits. It queries the resulting implementation space for the minimal resource tuples that meet the readiness and milestone requirements. It returns an actual trace for every retained tuple.
h(f) = Min { eval(i) : i ∈ I, f ≤ exec(i) }
The order on readiness curves is pointwise. The order on resource tuples compares each coordinate separately. “Minimal” allows several incomparable answers; there need not be one least or best plan.
Requirements may change. Commitments are another choice.
Monotonicity relates ordered requirements to feasible resource choices: asking more cannot make an inadequate implementation adequate. It does not mean that an exploratory slider may never be lowered. This model separately assumes that commissioned permanent tiers cannot decrease; mobile monitoring can be mobilised and released, and readiness during work can vary. Those are explicit transition rules, not consequences of the word “monotone”.
Explore the introductory coupling explanation · See exactly where categorical co-design is used
The counterexample concerns a missing interface
Projecting a path onto final readiness erases continuity. Under that projection, the cheap direct monitoring cutover can dominate the mobile-cover method. Once continuity is required, the cheap path can disappear and the enabling method becomes useful. Pareto reduction remains correct for the problem it was given. The endpoint-only problem omitted part of the promise.
What this does and does not establish
This gives a constructive positive result for a bounded version of the foray: staged wildlife-corridor co-design can produce feasible paths and a resource antichain when the action catalogue, constraints and temporal interface are explicit. It also locates the extra modelling work: co-design does not invent engineering methods, permissions or stakeholder preferences from a final readiness target.
Readiness bands, costs, slot lengths, cutovers and guards are fictional management requirements. Readiness is the minimum of passage, guide-fencing and monitoring bands because this brief requires all three. It is not a measurement of animal use, proof of ecological benefit or a claim that monitoring causes passage. Access units are a declared scarce planning resource. There is no species-response model, calibration, negotiation or safety approval. Stakeholder concerns appear only through the specified readiness, milestone and access constraints; this does not solve equitable negotiation.
What stays available during work
The toy catalogue assumes modular passage and fencing work alongside the existing provision, so each retains its previous band until slot end. Protected monitoring uses a prepared redundant arrangement. An active mobile team covers the currently commissioned monitoring band, including the higher band before a second cutover, at the declared fixed cost. Ongoing mobile-team staffing is included in that cost; the crew cap counts delivery actions. These are delivery assumptions to test, not field evidence. All guards read the start of the slot: fencing completed alongside passage work cannot enable that same passage upgrade.
Inspect the declared catalogue
Algorithm and evidence
All admissible finite choices are represented by the solver; the independent checker enumerates histories on smaller cases and compares feasible resource frontiers. Verification establishes the declared calculations, not usefulness to a human or a validated wildlife-corridor plan.
SOURCE IDEAS, MODEL CHOICES, TESTED RESULTS
Where the construction comes from.
A wildlife-corridor construction, with its mathematical sources, companion essays and recorded rail antecedents.
01
Design problems with implementation
Gioele Zardini, Co-Design of Complex Systems (2023), §§3.1–3.5, printed pp39–50. Supplies the functionality / implementation / resource separation and composition by admissible implementation tuples. This app chooses finite stage paths as those implementations.
Thesis at ETH Zürich ↗02
Minimal resource antichains
Andrea Censi, A Mathematical Theory of Co-Design (2015; revised 2016), with the MCDP manual’s catalogue examples and Monotone Co-Design Problems; or, everything is the same. Supplies the partial-order view of functionality and resource trade-offs. The JavaScript finite solver is independently written; it does not reproduce the general library or claim to implement its feedback solver.
Censi’s paper ↗ · Author’s papers & talks ↗03
Companion essays and preserved ideas
All four essays now use the wildlife corridor. The programme studio compares compatible finished packages and four supplied staging strategies; the component essay makes composition explicit; the feedback essay sizes batteries, conversion and cooling for off-grid monitoring. This path essay generates legal schedules. The coupling primer preserves explanations from the historical rail apps, correcting their request and monotonicity claims.
04
Temporal co-design already has antecedents
Corentin Briat’s 2026 codesign-mcdp library includes sequential and temporal extensions. The reviewed manual labels those extensions as work in preparation, not peer reviewed. Its carried-state implementation and regression example reinforce the need to preserve future resource consequences before projecting onto cost. This app uses its own finite solver.
Library paper ↗ · Reviewed sequential implementation ↗Contribution and boundary
The contribution is an executable end–way test for this foray, not a claim that temporal co-design or constrained planning is a new field. Each resource point is supported by a trace. Each infeasibility claim is restricted to the declared finite catalogue, time horizon and brief.
Inspect the app source ↗ · Model, source use and verification