31.2. Dimension one, three kind families, incommensurable special units (R13)
IEC 80000-13's characteristic quantities all live at dimension one — and this is exactly the place the catalogue's thesis turns into a unit question. Three families share dimension one but carry different special units, and belong to different kinds:
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Information content and entropy (13-24 …) in the shannon
Sh, hartleyHart, or natural unitnat— alternative units of one kind, related by the logarithm base. -
Traffic intensity (13-1 …) in the erlang
E. -
Storage capacity (13-9, 13-10) in the bit (or octet, or byte).
A dimension-only model sees one type, "a real number, dimension one", for all of them, and would let a bit of storage be silently read as an erlang of traffic. The shannon, erlang, and bit are scale-spanning units (R13), human-selected references for a dimensionless count — exactly like the candela (ISO 80000-7) and the mole (ISO 80000-9). The kind layer is what keeps them apart.
The shannon of information content and the erlang of traffic intensity are not
commensurable, though both are dimension one (items 13-24, 13-1). Two human-selected
dimensionless references for two different kinds — a bit of information is not an erlang of
traffic. The companion shannon_bit_not_commensurable separates information from storage.
This is the scale-spanning collision (R13) on information. Uses the
metrological unit.
Lean code for Theorem31.2.1●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part13.leancomplete
theorem PropertyKindCalculus.Iso80000.Part13.shannon_erlang_not_commensurable : ¬PropertyKindCalculus.Iso80000.Part13.shannon.Commensurable PropertyKindCalculus.Iso80000.Part13.erlang
theorem PropertyKindCalculus.Iso80000.Part13.shannon_erlang_not_commensurable : ¬PropertyKindCalculus.Iso80000.Part13.shannon.Commensurable PropertyKindCalculus.Iso80000.Part13.erlang
**The shannon of information content and the erlang of traffic intensity are not commensurable, though both are dimension one.** Two human-selected dimensionless references for two different kinds — a bit of information is not an erlang of traffic. The scale-spanning collision (R13) on information.
shannon_erlang_not_commensurable and shannon_bit_not_commensurable, each by decide
after unfolding MetrologicalUnit.Commensurable on the dimension-one kinds. Axiom-free.
The dimension-1 collision, on the standard. There exist distinct IEC 80000-13 kinds with the same dimension one — information content and traffic intensity witness it, alongside storage capacity, the entropies, and the probabilities. With distinct special units (shannon, erlang, bit), the dimension cannot separate them; the kind layer does. Uses the dimension map.
Lean code for Theorem31.2.2●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part13.leancomplete
theorem PropertyKindCalculus.Iso80000.Part13.iec80000_13_dim_one_collision : ∃ a b, a.kind LTMCTDimensionBase ≠ b.kind LTMCTDimensionBase ∧ a.dim LTMCTDimensionBase = b.dim LTMCTDimensionBase ∧ a.dim LTMCTDimensionBase = 1
theorem PropertyKindCalculus.Iso80000.Part13.iec80000_13_dim_one_collision : ∃ a b, a.kind LTMCTDimensionBase ≠ b.kind LTMCTDimensionBase ∧ a.dim LTMCTDimensionBase = b.dim LTMCTDimensionBase ∧ a.dim LTMCTDimensionBase = 1
**The dimension-one collision capstone, on the standard.** There exist distinct IEC 80000-13 kinds with the same dimension one — information content and traffic intensity witness it, alongside storage capacity, the entropies, and the probabilities. With distinct special units (shannon, erlang, bit), the {dimension functor} cannot separate them; the kind layer does.
iec80000_13_dim_one_collision, witnessed by ⟨informationContent, trafficIntensity, …⟩
with the kind distinction a decide and reflexivity. Axiom-free.