What ULM-PD Engine Is Not

Clarifying common misclassifications.

ULM-PD Engine occupies a space that can be easily misunderstood. This page exists to clarify what the system is not, in order to set correct expectations.


ULM-PD Engine is not a chatbot

ULM-PD Engine does not engage in open-ended conversation. Natural language is treated as uncertain input, not as dialogue.

Responses are generated only as a consequence of invariant-governed execution.

ULM-PD Engine is not a large language model

ULM-PD Engine does not generate output via probabilistic next-token prediction.

There is no optimisation for plausibility, fluency, or conversational helpfulness.

Execution proceeds only when declared invariants are satisfied.

ULM-PD Engine is not a “maths AI”

ULM-PD Engine does not guess, infer, or approximate results unless approximation is explicitly declared.

It executes calculations under invariant enforcement. If no valid state exists, execution halts.

ULM-PD Engine is not a SymPy wrapper

ULM-PD Engine is not a thin interface over any single library.

All operations are custom-built at the invariant level. Execution is driven by hand-authored invariants, constraints, and state rules that define what constitutes a valid calculation.

Internal computation may involve a variety of tools, but those tools are never authoritative. They are used only as execution substrates under ULM-PD Engine’s control.

Invariant enforcement, boundary handling, refusal semantics, and result representation are owned entirely by ULM-PD Engine.

ULM-PD Engine is not a best-effort solver

ULM-PD Engine does not attempt partial solutions, heuristic fallbacks, or plausible output.

Silence or refusal is preferred to incorrect results.

ULM-PD Engine is not a replacement for professional judgement

ULM-PD Engine enforces internal correctness under declared invariants.

It does not certify designs, approve regulatory compliance, or assume responsibility for real-world decisions.

Final responsibility remains with qualified practitioners, in accordance with applicable standards and regulations.


These clarifications are not limitations. They define the category of system ULM-PD Engine is designed to be.