21.1. Quantity-kinds and units of ISO 80000-3
A catalogued kind pairs a dimensioned quantity-kind with its exact source in the series — the part, the printed item designation (e.g. "3-3"), the principal quantity symbol, and the coherent SI unit symbol. The citation travels with the kind as data, so the source of each definition can be rendered or audited downstream rather than kept in a comment.
Lean code for Definition21.1.1●1 definition
Associated Lean declarations
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structuredefined in PropertyKindCalculus/Iso80000/Catalogue.leancomplete
structure PropertyKindCalculus.Iso80000.CataloguedKind : Type
structure PropertyKindCalculus.Iso80000.CataloguedKind : Type
A **catalogued quantity-kind**: a {dimensioned kind} together with its exact source in the 80000 series — the part, the printed item designation, the principal quantity symbol, and the coherent SI unit symbol. Every field other than `qk` is a *citation locator*; the citation travels with the kind as data, so a downstream model can render or audit the source of each definition. Shared by every part module, so the structure is defined once rather than per part.Fields
ref : PropertyKindCalculus.Iso80000.StandardRef
The part of the series this kind is defined in.
item : String
The item designation as printed, e.g. "3-3".
symbol : String
The principal quantity symbol, e.g. "A".
coherentUnit : String
The coherent SI unit symbol, e.g. "m²" (a citation locator).
qk : PropertyKindCalculus.DimensionedKind LTMCTDimensionBase
The dimensioned kind itself.
Realized as structure CataloguedKind over a DimensionedKind, with cite rendering
e.g. ISO 80000-3, Second edition, 2019-10 item 3-3. The catalogue lists all 42
items in item order — length (3-1.1), area (3-3), volume (3-4), duration (3-9), speed
(3-10.2), frequency (3-17.1), … — each paired with its coherent SI unit symbol.
Area is L² (item 3-3). The catalogued area kind carries length-exponent two in
PhysLib's dimension group — the standard's dimensional statement reproduced as a checked
computation, not an annotation. Uses the dimension map.
Lean code for Theorem21.1.2●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part3.leancomplete
theorem PropertyKindCalculus.Iso80000.Part3.area_dim_length : (PropertyKindCalculus.Iso80000.Part3.area.dim LTMCTDimensionBase).length = 2
theorem PropertyKindCalculus.Iso80000.Part3.area_dim_length : (PropertyKindCalculus.Iso80000.Part3.area.dim LTMCTDimensionBase).length = 2
Area is `L²`: its length-exponent is `2` (ISO 80000-3 item 3-3).
Proved as area_dim_length : area.dim.length = 2 in the Iso80000 library, discharged
by Dim.area_length from the Dimension layer. The companion volume_dim_length
(item 3-4) gives length-exponent three.
Speed is L·T⁻¹ (item 3-10.2). The catalogued speed kind's dimension equals length
divided by time — a checked computation in the dimension group. Uses
the dimension map.
Lean code for Theorem21.1.3●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part3.leancomplete
theorem PropertyKindCalculus.Iso80000.Part3.speed_dim : PropertyKindCalculus.Iso80000.Part3.speed.dim LTMCTDimensionBase = PropertyKindCalculus.Dim.length / PropertyKindCalculus.Dim.time
theorem PropertyKindCalculus.Iso80000.Part3.speed_dim : PropertyKindCalculus.Iso80000.Part3.speed.dim LTMCTDimensionBase = PropertyKindCalculus.Dim.length / PropertyKindCalculus.Dim.time
Speed is length over time (`L·T⁻¹`), ISO 80000-3 item 3-10.2.
Proved as speed_dim : speed.dim = Dim.length / Dim.time, discharged by Dim.speed_eq.
The catalogue also records curvature_dim_length = -1 (item 3-2, L⁻¹),
frequency_dim_time = -1 (item 3-17.1, T⁻¹), and acceleration_dim_time = -2
(item 3-11, L·T⁻²).
The metre is a well-formed unit (item 3-1.1). Length is a ratio-scale kind, so it bears a unit (Dybkær §13.3.5); the metre is one such chosen reference.
Lean code for Theorem21.1.4●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part3.leancomplete
theorem PropertyKindCalculus.Iso80000.Part3.metre_wellFormed : PropertyKindCalculus.Iso80000.Part3.metre.WellFormed
theorem PropertyKindCalculus.Iso80000.Part3.metre_wellFormed : PropertyKindCalculus.Iso80000.Part3.metre.WellFormed
The metre is a well-formed unit (length is ratio-scale, so it bears a unit).
Proved as metre_wellFormed : metre.WellFormed via
KindOfProperty.rational_bears_unit.
A metre and a second are not commensurable. Length and duration are distinct kinds, so their units cannot be compared by ratio — a type-level fact, not a runtime check. Uses metrological units.
Lean code for Theorem21.1.5●1 theorem
Associated Lean declarations
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theoremdefined in PropertyKindCalculus/Iso80000/Part3.leancomplete
theorem PropertyKindCalculus.Iso80000.Part3.metre_second_not_commensurable : ¬PropertyKindCalculus.Iso80000.Part3.metre.Commensurable PropertyKindCalculus.Iso80000.Part3.second
theorem PropertyKindCalculus.Iso80000.Part3.metre_second_not_commensurable : ¬PropertyKindCalculus.Iso80000.Part3.metre.Commensurable PropertyKindCalculus.Iso80000.Part3.second
The metre and the second are **not** commensurable — length and duration are distinct kinds (a type-level fact).
Proved as metre_second_not_commensurable : ¬ metre.Commensurable second by unfolding
Commensurable to the underlying kinds and decide (length's kind id differs from
duration's).