content: {-# LANGUAGE DataKinds #-}
  {-# LANGUAGE NumDecimals #-}
  
  {- |
     Copyright  : Copyright (C) 2006-2018 Bjorn Buckwalter
     License    : BSD3
  
     Maintainer : bjorn@buckwalter.se
     Stability  : Stable
     Portability: GHC only
  
  = Summary
  
  This module defines units that are not part of the SI, with the
  exception of those defined in the "Numeric.Units.Dimensional.SIUnits" module (units outside
  of the SI accepted for use with the SI).
  
  Any chapters, sections or tables referenced are from <#note1 [1]> unless
  otherwise specified.
  
  == Neper, bel, shannon and the like
  
  The units of section 5.1.2 are purposefully (but not permanently)
  omitted. In fact the logarithmic units (see section 8.7) are
  problematic and it is not clear how to implement them. Perhaps with
  a conversion function similar to for degrees Celsius.
  
  = References
  
  1. #note1# https://www.nist.gov/pml/special-publication-811
  2. #note2# https://www.iau.org/publications/proceedings_rules/units/
  3. #note3# https://en.wikipedia.org/wiki/Pressure
  4. #note4# https://en.wikipedia.org/wiki/Torr
  
  -}
  
  module Numeric.Units.Dimensional.NonSI
  (
    -- * Units Defined By Experiment
    -- $values-obtained-experimentally
    electronVolt, calorie, unifiedAtomicMassUnit, dalton,
    -- * Dimensionless Units
    percent,
    -- * Standard Gravity
    gee,
    -- * Inch-pound Units
    -- $inch-pound-units
    poundMass, ounce, poundForce, horsepower, btu, shortTon,
    nauticalMile, knot,
    revolution, solid,
    slug, psi,
    teaspoon,
    -- ** International Foot
    foot, inch, mil, yard, mile, acre,
    -- ** US Survey Foot
    usSurveyFoot, usSurveyInch, usSurveyMil, usSurveyYard, usSurveyMile, usSurveyAcre,
    -- * Years
    -- $year
    year, decade, century, millennium,
    -- * Pressure Units
    -- $pressure-units
    bar, atmosphere, technicalAtmosphere, mmHg, inHg, inHg_UCUM, inHg_NIST, torr,
    -- * Radiation Units
    rad,
    -- * Kinematic Viscosity
    stokes,
    -- * Temperature
    -- $temperature
    degreeFahrenheit, degreeRankine,
    -- * Imperial Volumes
    -- $imperial-volumes
    imperialGallon, imperialQuart, imperialPint, imperialCup, imperialGill, imperialFluidOunce,
    -- * US Customary Volumes
    -- $us-customary-volumes
    usGallon, usQuart, usPint, usCup, usGill, usFluidOunce,
    -- * Atomic-Scale Units
    angstrom,
    -- * Units from the Centimeter-Gram-Second Electrostatic System of Units
    gauss
  )
  where
  
  import Numeric.Units.Dimensional.Prelude
  import Numeric.Units.Dimensional.UnitNames.Internal (ucumMetric, ucum, dimensionalAtom)
  import qualified Prelude
  
  -- $setup
  -- >>> :set -fno-warn-type-defaults
  -- >>> import Data.ExactPi
  -- >>> import Data.Function (on)
  -- >>> import Numeric.Units.Dimensional.Coercion
  -- >>> default (Double)
  -- >>> :{
  -- >>>   let infix 4 ===
  -- >>>       (===) = areExactlyEqual `on` unQuantity :: Quantity d ExactPi -> Quantity d ExactPi -> Bool
  -- >>> :}
  
  {- $values-obtained-experimentally
  
  From Table 7, units accepted for use with the SI whose values in SI units are
  obtained experimentally.
  
  When <#note1 [1]> was published, the electron volt had a standard combined
  uncertainity of 0.00000049e-19 J and the unified atomic mass unit
  had a combined uncertainty of 0.0000010e-27 kg.
  
  -}
  
  electronVolt :: Floating a => Unit 'Metric DEnergy a
  electronVolt = mkUnitR (ucumMetric "eV" "eV" "electron volt") 1.60217733e-19 $ joule
  
  calorie :: Floating a => Unit 'Metric DEnergy a
  calorie = mkUnitR (ucumMetric "cal" "cal" "calorie") 4.184 $ joule
  
  unifiedAtomicMassUnit :: Floating a => Unit 'Metric DMass a
  unifiedAtomicMassUnit = mkUnitR (ucumMetric "u" "u" "atomic mass unit") 1.6605402e-27 $ kilo gram
  
  dalton :: Floating a => Unit 'Metric DMass a
  dalton = mkUnitR (ucumMetric "u" "Da" "Dalton") 1 $ unifiedAtomicMassUnit
  
  -- | One percent is one hundrendth.
  --
  -- The dimensionless number 0.01, represented by the symbol %, is commonly used as a dimensionless unit.
  --
  -- See section 7.10.2 of the <#note1 [1]> for further information.
  --
  -- >>> 1 *~ percent
  -- 1.0e-2
  percent :: (Fractional a) => Unit 'NonMetric DOne a
  percent = mkUnitQ (ucum "%" "%" "percent") (1 Prelude./ 100) one
  
  -- | One gee is the standard value of the acceleration due to gravity at the
  -- Earth's surface, as standardized by CIPM.
  --
  -- Note that local values of acceleration due to gravity will differ from the
  -- standard gravity.
  --
  -- See <https://en.wikipedia.org/wiki/Standard_gravity here> for further information.
  --
  -- >>> 1 *~ gee
  -- 9.80665 m s^-2
  --
  -- >>> 1 *~ gee :: Acceleration Rational
  -- 196133 % 20000 m s^-2
  gee :: Fractional a => Unit 'Metric DAcceleration a
  gee = mkUnitQ (ucumMetric "[g]" "g" "gee") 9.80665 $ meter / second ^ pos2
  
  {- $inch-pound-units
  Some US customary (that is, inch-pound) units.
  -}
  
  -- | One international foot is one third of an international 'yard'.
  --
  -- See <https://en.wikipedia.org/wiki/Foot_%28unit%29#International_foot here> for further information.
  --
  -- >>> 1 *~ foot
  -- 0.3048 m
  --
  -- prop> 3 *~ foot === 1 *~ yard
  --
  -- >>> 1 *~ foot :: Length Rational
  -- 381 % 1250 m
  foot :: Fractional a => Unit 'NonMetric DLength a
  foot = mkUnitQ (ucum "[ft_i]" "ft" "foot") (1 Prelude./ 3) $ yard
  
  -- | One inch is one twelth of a 'foot'.
  --
  -- This inch is based on the international 'foot'.
  --
  -- See <https://en.wikipedia.org/wiki/Inch#Modern_standardisation here> for further information.
  --
  -- >>> 1 *~ inch
  -- 2.54e-2 m
  --
  -- prop> 12 *~ inch === 1 *~ foot
  --
  -- >>> 1 *~ inch :: Length Rational
  -- 127 % 5000 m
  inch :: Fractional a => Unit 'NonMetric DLength a
  inch = mkUnitQ (ucum "[in_i]" "in" "inch") (1 Prelude./ 12) $ foot
  
  -- | One mil is one thousandth of an 'inch'.
  --
  -- This mil is based on the international 'inch'.
  --
  -- See <https://en.wikipedia.org/wiki/Thousandth_of_an_inch here> for further information.
  --
  -- >>> 1 *~ mil
  -- 2.54e-5 m
  --
  -- prop> 1000 *~ mil === 1 *~ inch
  --
  -- >>> 1 *~ mil :: Length Rational
  -- 127 % 5000000 m
  mil :: Fractional a => Unit 'NonMetric DLength a
  mil = mkUnitQ (ucum "[mil_i]" "mil" "mil") 0.001 $ inch
  
  -- | One yard, as defined by international agreement in 1959, is precisely
  -- 0.9144 'meter'.
  --
  -- See <https://en.wikipedia.org/wiki/Yard here> for further information.
  --
  -- >>> 1 *~ yard
  -- 0.9144 m
  --
  -- >>> 1 *~ yard :: Length Rational
  -- 1143 % 1250 m
  yard :: (Fractional a) => Unit 'NonMetric DLength a
  yard = mkUnitQ (ucum "[yd_i]" "yd" "yard") 0.9144 $ meter
  
  -- | One mile is 5 280 feet.
  --
  -- This mile is based on the international 'foot'.
  --
  -- See <https://en.wikipedia.org/wiki/Mile#International_mile here> for further information.
  --
  -- >>> 1 *~ mile
  -- 1609.344 m
  --
  -- prop> 1 *~ mile === 5280 *~ foot
  --
  -- >>> 1 *~ mile :: Length Rational
  -- 201168 % 125 m
  mile :: (Fractional a) => Unit 'NonMetric DLength a
  mile = mkUnitQ (ucum "[mi_i]" "mi" "mile") 5280 $ foot
  
  -- | One acre is 43 560 square feet.
  --
  -- This acre is based on the international 'foot'. For the acre based on the US Survey Foot,
  -- see 'usSurveyAcre'. While both acres are in use, the difference between them is of little consequence
  -- for most applications in which either is used.
  --
  -- See <https://en.wikipedia.org/wiki/Acre#Differences_between_international_and_US_survey_acres here> for further information.
  --
  -- >>> 1 *~ acre
  -- 4046.8564224 m^2
  --
  -- prop> 1 *~ acre === 43560 *~ foot ^ pos2
  --
  -- >>> 1 *~ acre :: Area Rational
  -- 316160658 % 78125 m^2
  acre :: (Fractional a) => Unit 'NonMetric DArea a
  acre = mkUnitQ (dimensionalAtom "[acr_i]" "ac" "acre") 43560 $ square foot
  
  -- | One US survey foot is 1200/3937 'meter'.
  --
  -- For the international foot, see 'foot'. Note that this is not the foot in routine use
  -- in the United States.
  --
  -- See <https://en.wikipedia.org/wiki/Foot_%28unit%29#US_survey_foot here> for further information.
  --
  -- >>> 1 *~ usSurveyFoot
  -- 0.3048006096012192 m
  --
  -- >>> 1 *~ usSurveyFoot :: Length Rational
  -- 1200 % 3937 m
  usSurveyFoot :: Fractional a => Unit 'NonMetric DLength a
  usSurveyFoot = mkUnitQ (ucum "[ft_us]" "ft" "foot") (1200 Prelude./ 3937) $ meter
  
  -- | One inch is one twelth of a foot.
  --
  -- This inch is based on the 'usSurveyFoot'. For the inch based on the international foot,
  -- see 'inch'. Note that this is not the inch in routine use in the United States.
  --
  -- See <https://en.wikipedia.org/wiki/Inch here> for further information.
  --
  -- >>> 1 *~ usSurveyInch
  -- 2.54000508001016e-2 m
  --
  -- prop> 12 *~ usSurveyInch === 1 *~ usSurveyFoot
  --
  -- >>> 1 *~ usSurveyInch :: Length Rational
  -- 100 % 3937 m
  usSurveyInch :: Fractional a => Unit 'NonMetric DLength a
  usSurveyInch = mkUnitQ (ucum "[in_us]" "in" "inch") (1 Prelude./ 12) $ usSurveyFoot
  
  -- | One mil is one thousandth of an inch.
  --
  -- This mil is based on the 'usSurveyInch'. For the mil based on the international inch,
  -- see 'mil'. Note that this is not the mil in routine use in the United States.
  --
  -- See <https://en.wikipedia.org/wiki/Thousandth_of_an_inch here> for further information.
  --
  -- >>> 1 *~ usSurveyMil
  -- 2.54000508001016e-5 m
  --
  -- prop> 1000 *~ usSurveyMil === 1 *~ usSurveyInch
  --
  -- >>> 1 *~ usSurveyMil :: Length Rational
  -- 1 % 39370 m
  usSurveyMil :: Fractional a => Unit 'NonMetric DLength a
  usSurveyMil = mkUnitQ (ucum "[mil_us]" "mil" "mil") 0.001 $ usSurveyInch
  
  -- | One yard is three feet.
  --
  -- This yard is based on the 'usSurveyFoot'. For the international yard,
  -- see 'yard'. Note that this is not the yard in routine use in the United States.
  --
  -- See <https://en.wikipedia.org/wiki/Yard here> for further information.
  --
  -- >>> 1 *~ usSurveyYard
  -- 0.9144018288036576 m
  --
  -- prop> 1 *~ usSurveyYard === 3 *~ usSurveyFoot
  --
  -- >>> 1 *~ usSurveyYard :: Length Rational
  -- 3600 % 3937 m
  usSurveyYard :: (Fractional a) => Unit 'NonMetric DLength a
  usSurveyYard = mkUnitQ (ucum "[yd_us]" "yd" "yard") 3 $ usSurveyFoot
  
  -- | One US survey mile is 5 280 US survey feet.
  --
  -- This mile is based on the 'usSurveyFoot'. For the mile based on the international foot,
  -- see 'mile'. Note that this is not the mile in routine use in the United States.
  --
  -- See <https://en.wikipedia.org/wiki/Mile#US_survey_mile here> for further information.
  --
  -- >>> 1 *~ usSurveyMile
  -- 1609.3472186944373 m
  --
  -- prop> 1 *~ usSurveyMile === 5280 *~ usSurveyFoot
  --
  -- >>> 1 *~ usSurveyMile :: Length Rational
  -- 6336000 % 3937 m
  usSurveyMile :: (Fractional a) => Unit 'NonMetric DLength a
  usSurveyMile = mkUnitQ (ucum "[mi_us]" "mi" "mile") 5280 $ usSurveyFoot
  
  -- | One acre is 43 560 square feet.
  --
  -- This acre is based on the 'usSurveyFoot'. For the acre based on the international foot,
  -- see 'acre'. While both acres are in use, the difference between them is of little consequence
  -- for most applications in which either is used. This is the only acre defined by the UCUM.
  --
  -- See <https://en.wikipedia.org/wiki/Acre#Differences_between_international_and_US_survey_acres here> for further information.
  --
  -- >>> 1 *~ usSurveyAcre
  -- 4046.872609874252 m^2
  --
  -- prop> 1 *~ usSurveyAcre === 43560 *~ usSurveyFoot ^ pos2
  --
  -- >>> 1 *~ usSurveyAcre :: Area Rational
  -- 62726400000 % 15499969 m^2
  usSurveyAcre :: (Fractional a) => Unit 'NonMetric DArea a
  usSurveyAcre = mkUnitQ (ucum "[acr_us]" "ac" "acre") 43560 $ square usSurveyFoot
  
  -- | One avoirdupois pound is a mass, exactly defined in terms of the kilogram by the international
  -- yard and pound agreement of 1959.
  --
  -- See <https://en.wikipedia.org/wiki/Avoirdupois#Internationalization here> for further information.
  --
  -- >>> 1 *~ poundMass
  -- 0.45359237 kg
  --
  -- >>> 1 *~ poundMass :: Mass Rational
  -- 45359237 % 100000000 kg
  poundMass :: Fractional a => Unit 'NonMetric DMass a
  poundMass = mkUnitQ (ucum "[lb_av]" "lb" "pound") 0.45359237 $ kilo gram
  
  -- | One avoirdupois ounce is one sixteenth of a 'poundMass'.
  --
  -- See <https://en.wikipedia.org/wiki/Ounce#International_avoirdupois_ounce here> for further information.
  --
  -- >>> 1 *~ ounce
  -- 2.8349523125e-2 kg
  --
  -- prop> 16 *~ ounce === 1 *~ poundMass
  --
  -- >>> 1 *~ ounce :: Mass Rational
  -- 45359237 % 1600000000 kg
  ounce :: Fractional a => Unit 'NonMetric DMass a
  ounce = mkUnitQ (ucum "[oz_av]" "oz" "ounce") (1 Prelude./ 16) $ poundMass
  
  -- | One short ton is two thousand 'poundMass'.
  --
  -- See <https://en.wikipedia.org/wiki/Short_ton#United_States here> for further information.
  --
  -- >>> 1 *~ shortTon
  -- 907.18474 kg
  --
  -- >>> 1 *~ shortTon :: Mass Rational
  -- 45359237 % 50000 kg
  shortTon :: Fractional a => Unit 'NonMetric DMass a
  shortTon = mkUnitQ (ucum "[ston_av]" "ton" "short ton") 2000 $ poundMass
  
  -- | The pound-force is equal to the gravitational force exerted on a mass
  -- of one avoirdupois pound on the surface of Earth.
  --
  -- This definition is based on standard gravity (the 'gee') and the
  -- international avoirdupois 'poundMass'.
  --
  -- See <https://en.wikipedia.org/wiki/Pound_%28force%29 here> for further information.
  --
  -- >>> 1 *~ poundForce
  -- 4.4482216152605 m kg s^-2
  --
  -- prop> 1 *~ poundForce === 1 *~ poundMass * (1 *~ gee)
  --
  -- >>> 1 *~ poundForce :: Force Rational
  -- 8896443230521 % 2000000000000 m kg s^-2
  poundForce :: Fractional a => Unit 'NonMetric DForce a
  poundForce = mkUnitQ (ucum "[lbf_av]" "lbf" "pound force") 1 $ poundMass * gee
  
  -- | One mechanical horsepower is by definition the power necessary
  -- to apply a force of 550 'poundForce' through a distance of one 'foot'
  -- per 'second'.
  --
  -- See <https://en.wikipedia.org/wiki/Horsepower#Mechanical_horsepower here> for further information.
  --
  -- >>> 1 *~ horsepower
  -- 745.6998715822702 m^2 kg s^-3
  --
  -- prop> 1 *~ horsepower === 550 *~ poundForce * (1 *~ foot) / (1 *~ second)
  --
  -- >>> 1 *~ horsepower :: Power Rational
  -- 37284993579113511 % 50000000000000 m^2 kg s^-3
  horsepower :: Fractional a => Unit 'NonMetric DPower a
  horsepower = mkUnitQ (ucum "[HP]" "hp" "horsepower") 550 $ foot * poundForce / second
  
  -- | The slug is a unit of mass associated with Imperial units and United States customary units.
  -- It is a mass that accelerates by 1 foot per second per second when a force of one pound is exerted on it.
  --
  -- This definition is based on standard gravity (the 'gee'), the international 'foot', and the international avoirdupois 'poundMass'.
  --
  -- See <https://en.wikipedia.org/wiki/Slug_%28mass%29 here> for further information.
  --
  -- >>> 1 *~ slug
  -- 14.593902937206364 kg
  --
  -- >>> 1 *~ slug :: Mass Rational
  -- 8896443230521 % 609600000000 kg
  slug :: Fractional a => Unit 'NonMetric DMass a
  slug = mkUnitQ (dimensionalAtom "slug" "slug" "slug") 1 $ poundForce * (second^pos2) / foot
  
  -- | One psi is a pressure of one 'poundForce' per 'square' 'inch' of area.
  --
  -- See <https://en.wikipedia.org/wiki/Pounds_per_square_inch here> for further information.
  --
  -- >>> 1 *~ psi
  -- 6894.757293168362 m^-1 kg s^-2
  --
  -- >>> 1 *~ psi :: Pressure Rational
  -- 8896443230521 % 1290320000 m^-1 kg s^-2
  psi :: Fractional a => Unit 'NonMetric DPressure a
  psi = mkUnitQ (ucum "[psi]" "psi" "pound per square inch") 1 $ poundForce / inch ^ pos2
  
  -- | One nautical mile is a unit of length, set by international agreement as being exactly 1 852 meters.
  --
  -- Historically, it was defined as the distance spanned by one minute of arc along a meridian of the Earth.
  --
  -- See <https://en.wikipedia.org/wiki/Nautical_mile here> for further information.
  --
  -- >>> 1 *~ nauticalMile
  -- 1852.0 m
  --
  -- >>> 1 *~ nauticalMile :: Length Rational
  -- 1852 % 1 m
  nauticalMile :: (Num a) => Unit 'NonMetric DLength a
  nauticalMile = mkUnitZ (ucum "[nmi_i]" "NM" "nautical mile") 1852 $ meter
  
  -- | One knot is a velocity equal to one 'nauticalMile' per 'hour'.
  --
  -- See <https://en.wikipedia.org/wiki/Knot_%28unit%29 here> for further information.
  --
  -- >>> 1 *~ knot
  -- 0.5144444444444445 m s^-1
  --
  -- >>> 1 *~ knot :: Velocity Rational
  -- 463 % 900 m s^-1
  knot :: (Fractional a) => Unit 'NonMetric DVelocity a
  knot = mkUnitQ (ucum "[kt_i]" "kt" "knot") 1 $ nauticalMile / hour
  
  -- | One revolution is an angle equal to 2*pi radians; a full circle.
  --
  -- See <https://en.wikipedia.org/wiki/Turn_%28geometry%29 here> for further information.
  --
  -- >>> 1 *~ revolution
  -- 6.283185307179586
  --
  -- prop> 1 *~ revolution === _2 * pi * (1 *~ radian)
  --
  -- prop> 1 *~ revolution === 360 *~ degree
  revolution :: (Floating a) => Unit 'NonMetric DOne a
  revolution = mkUnitR (dimensionalAtom "rev" "rev" "revolution") (2 Prelude.* Prelude.pi) $ radian
  
  solid :: (Floating a) => Unit 'NonMetric DOne a
  solid = mkUnitR (dimensionalAtom "solid" "solid" "solid") (4 Prelude.* Prelude.pi) $ steradian
  
  teaspoon :: (Fractional a) => Unit 'NonMetric DVolume a
  teaspoon = mkUnitQ (ucum "[tsp_m]" "tsp" "teaspoon") 5 $ milli liter
  
  -- | One btu is is the 'QuantityOfHeat' required to raise the temperature
  -- of 1 avoirdupois 'poundMass' of liquid water by 1 'degreeFahrenheit' at a constant pressure of one 'atmosphere'.
  --
  -- Because this value must be determined experimentally and varies with temperature, several standardized
  -- values of the btu have arisen. This is the value based on the International Steam Table calorie,
  -- defined by the Fifth International Conference on the Properties of Steam.
  --
  -- See <https://en.wikipedia.org/wiki/British_thermal_unit#Definitions here> for further information.
  --
  -- >>> 1 *~ btu
  -- 1055.05585262 m^2 kg s^-2
  --
  -- >>> 1 *~ btu :: Energy Rational
  -- 52752792631 % 50000000 m^2 kg s^-2
  btu :: Fractional a => Unit 'NonMetric DEnergy a
  btu = mkUnitQ (ucum "[Btu_IT]" "btu" "British thermal unit") 1055.05585262 $ joule
  
  
  {- $year
  
  The IAU recommends <#note2 [2]> that:
  
    Although there are several different kinds of year (as there are
    several kinds of day), it is best to regard a year as a Julian
    year of 365.25 days (31557600 s) unless otherwise specified.
  
  -}
  
  -- | One Julian year is a unit of measurement of time defined as exactly 365.25 days of 86 400 'second's each.
  --
  -- See <https://en.wikipedia.org/wiki/Julian_year_%28astronomy%29 here> for further information.
  --
  -- prop> 1 *~ year === 365.25 *~ day
  --
  -- >>> 1 *~ year
  -- 3.15576e7 s
  --
  -- >>> 1 *~ year :: Time Rational
  -- 31557600 % 1 s
  year :: Num a => Unit 'NonMetric DTime a
  year = mkUnitZ (ucum "a_j" "a" "mean Julian year") 31557600 $ second
  
  -- | One Julian decade is ten Julian 'year's.
  --
  -- prop> 1 *~ decade === 10 *~ year
  --
  -- >>> 1 *~ decade
  -- 3.15576e8 s
  --
  -- >>> 1 *~ decade :: Time Rational
  -- 315576000 % 1 s
  decade :: Num a => Unit 'NonMetric DTime a
  decade = mkUnitZ (dimensionalAtom "d_j" "dec" "mean Julian decade") 10 $ year
  
  -- | One Julian century is one hundred Julian 'year's, or 35 525 'day's of 86 400 'second's each.
  --
  -- prop> 1 *~ century === 100 *~ year
  --
  -- prop> 1 *~ century === 36525 *~ day
  --
  -- >>> 1 *~ century
  -- 3.15576e9 s
  --
  -- >>> 1 *~ century :: Time Rational
  -- 3155760000 % 1 s
  century :: Num a => Unit 'NonMetric DTime a
  century = mkUnitZ (dimensionalAtom "c_j" "cen" "mean Julian century") 100 $ year
  
  -- | One Julian millennium is one thousand Julian 'year's.
  --
  -- prop> 1 *~ millennium === 1000 *~ year
  --
  -- >>> 1 *~ millennium
  -- 3.15576e10 s
  --
  -- >>> 1 *~ millennium :: Time Rational
  -- 31557600000 % 1 s
  millennium :: Num a => Unit 'NonMetric DTime a
  millennium = mkUnitZ (dimensionalAtom "m_j" "mil" "mean Julian millennium") 1000 $ year
  
  {- $pressure-units
  It seems that nearly every area of application has its own customary unit for measuring pressure.
  We include some of the common ones here. 'psi' was defined earlier.
  -}
  
  -- | The bar is exactly 100 000 'Numeric.Units.Dimensional.SIUnits.pascal'.
  --
  -- From Wikipedia:
  --
  --  It is about equal to the atmospheric pressure on Earth at sea level.
  --
  -- >>> 1 *~ bar
  -- 100000.0 m^-1 kg s^-2
  --
  -- >>> 1 *~ bar :: Pressure Rational
  -- 100000 % 1 m^-1 kg s^-2
  bar :: (Num a) => Unit 'Metric DPressure a
  bar = mkUnitZ (ucumMetric "bar" "bar" "bar") 1e5 $ pascal
  
  -- | The "standard atmosphere".
  --
  -- From Wikipedia <#note3 [3]>:
  --
  --  The standard atmosphere (atm) is an established constant. It is
  --  approximately equal to typical air pressure at earth mean sea
  --  level.
  --
  -- >>> 1 *~ atmosphere
  -- 101325.0 m^-1 kg s^-2
  --
  -- >>> 1 *~ atmosphere :: Pressure Rational
  -- 101325 % 1 m^-1 kg s^-2
  atmosphere :: (Num a) => Unit 'NonMetric DPressure a
  atmosphere = mkUnitZ (ucum "atm" "atm" "standard atmosphere") 101325 $ pascal
  
  -- | The "technical atmosphere"
  --
  -- From Wikipedia:
  --
  --  A technical atmosphere (symbol: at) is a non-SI unit of pressure equal
  --  to one kilogram-force per square centimeter.
  --
  -- >>> 1 *~ technicalAtmosphere
  -- 98066.5 m^-1 kg s^-2
  --
  -- >>> 1 *~ technicalAtmosphere :: Pressure Rational
  -- 196133 % 2 m^-1 kg s^-2
  technicalAtmosphere :: (Fractional a) => Unit 'NonMetric DPressure a
  technicalAtmosphere = mkUnitQ (ucum "att" "at" "technical atmosphere") 1 $ kilo gram * gee * centi meter ^ neg2
  
  -- | The conventional value for the pressure exerted by a 1 mm high column of mercury.
  --
  -- Per Wikipedia <#note4 [4]>, one mmHg (millimeter of mercury) is defined as:
  --
  --  The pressure exerted at the base of a column of fluid exactly 1 mm high,
  --  when the density of the fluid is exactly 13.5951 g/cm^3, at a place
  --  where the acceleration of gravity is exactly 9.80665 m/s^2.
  --
  -- The chosen fluid density approximately corresponds to that of mercury
  -- at 0 deg. Under most conditions, 1 mmHg is approximately equal to 1 'torr'.
  --
  -- >>> 1 *~ mmHg
  -- 133.322 m^-1 kg s^-2
  --
  -- >>> 1 *~ mmHg :: Pressure Rational
  -- 66661 % 500 m^-1 kg s^-2
  mmHg :: (Fractional a) => Unit 'NonMetric DPressure a
  mmHg = milli mHg
  
  mHg :: (Fractional a) => Unit 'Metric DPressure a
  mHg = mkUnitQ (ucumMetric "m[Hg]" "m Hg" "meter of mercury") 133.3220 $ kilo pascal
  
  -- | The conventional value for the pressure exerted by a 1 inch high column of mercury.
  --
  -- Column inches of mercury are also used to measure pressure, especially in
  -- meteorological or aeronautical contexts in the United States.
  --
  -- This is the value defined by UCUM. For the value defined by NIST, see 'inHg_NIST'.
  --
  -- >>> 1 *~ inHg
  -- 3386.3788 m^-1 kg s^-2
  --
  -- >>> 1 *~ inHg :: Pressure Rational
  -- 8465947 % 2500 m^-1 kg s^-2
  inHg :: (Fractional a) => Unit 'NonMetric DPressure a
  inHg = inHg_UCUM
  
  -- | The conventional value for the pressure exerted by a 1 inch high column of mercury.
  --
  -- Column inches of mercury are also used to measure pressure, especially in
  -- meteorological or aeronautical contexts in the United States.
  --
  -- This is the value defined by UCUM. For the value defined by NIST, see 'inHg_NIST'.
  --
  -- >>> 1 *~ inHg_UCUM
  -- 3386.3788 m^-1 kg s^-2
  --
  -- >>> 1 *~ inHg_UCUM :: Pressure Rational
  -- 8465947 % 2500 m^-1 kg s^-2
  inHg_UCUM :: (Fractional a) => Unit 'NonMetric DPressure a
  inHg_UCUM = mkUnitQ (ucum "[in_i'Hg]" "in Hg" "inch of mercury") 1 $ mHg * inch / meter
  
  -- | The conventional value for the pressure exerted by a 1 inch high column of mercury.
  --
  -- Column inches of mercury are also used to measure pressure, especially in
  -- meteorological or aeronautical contexts in the United States.
  --
  -- This is the value defined by NIST. For the value defined by UCUM, see 'inHg_UCUM'.
  --
  -- >>> 1 *~ inHg_NIST
  -- 3386.389 m^-1 kg s^-2
  --
  -- >>> 1 *~ inHg_NIST :: Pressure Rational
  -- 3386389 % 1000 m^-1 kg s^-2
  inHg_NIST :: (Fractional a) => Unit 'NonMetric DPressure a
  inHg_NIST = mkUnitQ (dimensionalAtom "[in_i'Hg_NIST]" "in Hg" "inch of mercury") 3.386389e3 $ pascal
  
  -- | One torr (symbol: Torr) is defined as 1/760 'atmosphere', which is approximately equal to 1 'mmHg'.
  --
  -- See <https://en.wikipedia.org/wiki/Torr here> for further information.
  --
  -- >>> 1 *~ torr
  -- 133.32236842105263 m^-1 kg s^-2
  --
  -- >>> 1 *~ torr :: Pressure Rational
  -- 20265 % 152 m^-1 kg s^-2
  torr :: (Fractional a) => Unit 'NonMetric DPressure a
  torr = mkUnitQ (dimensionalAtom "Torr" "Torr" "Torr") (1 Prelude./ 760) $ atmosphere
  
  -- | The rad is a deprecated unit of 'AbsorbedDose', defined as
  -- 0.01 'gray'.
  --
  -- See <https://en.wikipedia.org/wiki/Rad_%28unit%29 here> for further information.
  --
  -- >>> 1 *~ rad
  -- 1.0e-2 m^2 s^-2
  --
  -- >>> 1 *~ rad :: AbsorbedDose Rational
  -- 1 % 100 m^2 s^-2
  rad :: (Fractional a) => Unit 'Metric DAbsorbedDose a
  rad = mkUnitQ (ucumMetric "RAD" "RAD" "RAD") 1 $ centi gray
  
  -- | One Stokes is a unit of 'KinematicViscosity' equal to @1 cm^2 / s@.
  --
  -- See <https://en.wikipedia.org/wiki/Viscosity#Kinematic_viscosity_.CE.BD here> for further information.
  --
  -- >>> 1 *~ stokes
  -- 1.0e-4 m^2 s^-1
  --
  -- >>> 1 *~ stokes :: KinematicViscosity Rational
  -- 1 % 10000 m^2 s^-1
  stokes :: (Fractional a) => Unit 'Metric DKinematicViscosity a
  stokes = mkUnitQ (ucumMetric "St" "St" "Stokes") 1 $ centi meter ^ pos2 / second
  
  {- $temperature
  These units of temperature are relative. For absolute temperatures, see 'Numeric.Units.Dimensional.SIUnits.fromDegreeCelsiusAbsolute'.
  -}
  
  -- | One degree Fahrenheit is a unit of relative temperature equal to 5/9 'kelvin'.
  --
  -- Note that although the Fahrenheit scale is an absolute temperature scale, this unit is a unit of difference within
  -- that scale and measures relative temperature.
  --
  -- See <https://en.wikipedia.org/wiki/Fahrenheit#Definition_and_conversions here> for further information.
  --
  -- >>> 1 *~ degreeFahrenheit
  -- 0.5555555555555556 K
  --
  -- >>> 1 *~ degreeFahrenheit :: ThermodynamicTemperature Rational
  -- 5 % 9 K
  degreeFahrenheit :: (Fractional a) => Unit 'NonMetric DThermodynamicTemperature a
  degreeFahrenheit = mkUnitQ (ucum "[degF]" "°F" "degree Fahrenheit") (5 Prelude./ 9) $ degreeCelsius
  
  -- | One degree Rankine is a unit of relative temperature equal to 5/9 'kelvin'.
  --
  -- Note that although the Rankine scale is an absolute temperature scale, this unit is a unit of difference within
  -- that scale and measures relative temperature.
  --
  -- See <https://en.wikipedia.org/wiki/Rankine_scale here> for further information.
  --
  -- >>> 1 *~ degreeRankine
  -- 0.5555555555555556 K
  --
  -- >>> 1 *~ degreeRankine :: ThermodynamicTemperature Rational
  -- 5 % 9 K
  degreeRankine :: (Fractional a) => Unit 'NonMetric DThermodynamicTemperature a
  degreeRankine = mkUnitQ (ucum "[degR]" "°R" "degree Rankine") 1 $ degreeFahrenheit
  
  {- $imperial-volumes
  Per https://en.wikipedia.org/wiki/Imperial_units and https://en.wikipedia.org/wiki/Cup_(unit)#Imperial_cup.
  -}
  
  -- | One imperial gallon is defined exactly in terms of the 'liter'
  -- by the Weights and Measures Act 1985.
  --
  -- See <https://en.wikipedia.org/wiki/Imperial_units#Volume here> for further information.
  --
  -- >>> 1 *~ imperialGallon
  -- 4.54609e-3 m^3
  --
  -- >>> 1 *~ imperialGallon :: Volume Rational
  -- 454609 % 100000000 m^3
  imperialGallon :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialGallon = mkUnitQ (ucum "[gal_br]" "gal" "gallon") 4.54609 $ liter
  
  -- | One imperial quart is one quarter of an 'imperialGallon'.
  --
  -- See <https://en.wikipedia.org/wiki/Imperial_units#Volume here> for further information.
  --
  -- >>> 1 *~ imperialQuart
  -- 1.1365225e-3 m^3
  --
  -- >>> 1 *~ imperialQuart :: Volume Rational
  -- 454609 % 400000000 m^3
  imperialQuart :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialQuart = mkUnitQ (ucum "[qt_br]" "qt" "quart") (1 Prelude./ 4) $ imperialGallon
  
  -- | One imperial pint is one half of an 'imperialQuart'.
  --
  -- See <https://en.wikipedia.org/wiki/Imperial_units#Volume here> for further information.
  --
  -- >>> 1 *~ imperialPint
  -- 5.6826125e-4 m^3
  --
  -- >>> 1 *~ imperialPint :: Volume Rational
  -- 454609 % 800000000 m^3
  imperialPint :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialPint = mkUnitQ (ucum "[pt_br]" "pt" "pint") (1 Prelude./ 8) $ imperialGallon
  
  -- | One imperial cup is one half of an 'imperialPint'.
  --
  -- This unit is not in common use and is does not appear in some sources
  -- describing the imperial fluid volume units.
  --
  -- See <https://en.wikipedia.org/wiki/Cup_%28unit%29#Imperial_cup here> for further information.
  --
  -- >>> 1 *~ imperialCup
  -- 2.84130625e-4 m^3
  --
  -- >>> 1 *~ imperialCup :: Volume Rational
  -- 454609 % 1600000000 m^3
  imperialCup :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialCup = mkUnitQ (dimensionalAtom "[cup_br]" "cup" "cup") 0.5 $ imperialPint
  
  -- | One imperial gill is one quarter of an 'imperialPint'.
  --
  -- See <https://en.wikipedia.org/wiki/Imperial_units#Volume here> for further information.
  --
  -- >>> 1 *~ imperialGill
  -- 1.420653125e-4 m^3
  --
  -- >>> 1 *~ imperialGill :: Volume Rational
  -- 454609 % 3200000000 m^3
  imperialGill :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialGill = mkUnitQ (ucum "[gil_br]" "gill" "gill") (1 Prelude./ 4) $ imperialPint
  
  -- | One imperial fluid ounce is one twentieth of an 'imperialPint'.
  --
  -- See <https://en.wikipedia.org/wiki/Imperial_units#Volume here> for further information.
  --
  -- >>> 1 *~ imperialFluidOunce
  -- 2.84130625e-5 m^3
  --
  -- >>> 1 *~ imperialFluidOunce :: Volume Rational
  -- 454609 % 16000000000 m^3
  imperialFluidOunce :: (Fractional a) => Unit 'NonMetric DVolume a
  imperialFluidOunce = mkUnitQ (ucum "[foz_br]" "fl oz" "fluid ounce") (1 Prelude./ 20) $ imperialPint
  
  {- $us-customary-volumes
  Per https://www.nist.gov/system/files/documents/2017/05/09/2012-hb44-final.pdf page 452 and https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume
  Note that there exist rarely-used "dry" variants of units with overlapping names.
  -}
  
  -- | One US liquid gallon is a volume of 231 cubic inches.
  --
  -- See <https://en.wikipedia.org/wiki/Gallon#The_US_liquid_gallon here> for further information.
  --
  -- >>> 1 *~ usGallon
  -- 3.785411784e-3 m^3
  --
  -- >>> 1 *~ usGallon :: Volume Rational
  -- 473176473 % 125000000000 m^3
  usGallon :: (Fractional a) => Unit 'NonMetric DVolume a
  usGallon = mkUnitQ (ucum "[gal_us]" "gal" "gallon") 231 $ cubic inch
  
  -- | One US liquid quart is one quarter of a 'usGallon'.
  --
  -- See <https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume here> for further information.
  --
  -- >>> 1 *~ usQuart
  -- 9.46352946e-4 m^3
  --
  -- >>> 1 *~ usQuart :: Volume Rational
  -- 473176473 % 500000000000 m^3
  usQuart :: (Fractional a) => Unit 'NonMetric DVolume a
  usQuart = mkUnitQ (ucum "[qt_us]" "qt" "quart") (1 Prelude./ 4) $ usGallon
  
  -- | One US liquid pint is one half of a 'usQuart'.
  --
  -- See <https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume here> for further information.
  --
  -- >>> 1 *~ usPint
  -- 4.73176473e-4 m^3
  --
  -- >>> 1 *~ usPint :: Volume Rational
  -- 473176473 % 1000000000000 m^3
  usPint :: (Fractional a) => Unit 'NonMetric DVolume a
  usPint = mkUnitQ (ucum "[pt_us]" "pt" "pint") (1 Prelude./ 8) $ usGallon
  
  -- | One US liquid cup is one half of a 'usPint'.
  --
  -- See <https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume here> for further information.
  --
  -- >>> 1 *~ usCup
  -- 2.365882365e-4 m^3
  --
  -- >>> 1 *~ usCup :: Volume Rational
  -- 473176473 % 2000000000000 m^3
  usCup :: (Fractional a) => Unit 'NonMetric DVolume a
  usCup = mkUnitQ (ucum "[cup_us]" "cup" "cup") (1 Prelude./ 2) $ usPint
  
  -- | One US liquid gill is one half of a 'usCup'.
  --
  -- See <https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume here> for further information.
  --
  -- >>> 1 *~ usGill
  -- 1.1829411825e-4 m^3
  --
  -- >>> 1 *~ usGill :: Volume Rational
  -- 473176473 % 4000000000000 m^3
  usGill :: (Fractional a) => Unit 'NonMetric DVolume a
  usGill = mkUnitQ (ucum "[gil_us]" "gill" "gill") (1 Prelude./ 4) $ usPint
  
  -- | One US fluid ounce is 1/128 'usGallon' or 1/8 'usCup'.
  --
  -- See <https://en.wikipedia.org/wiki/United_States_customary_units#Fluid_volume here> for further information.
  --
  -- >>> 1 *~ usFluidOunce
  -- 2.95735295625e-5 m^3
  --
  -- >>> 1 *~ usFluidOunce :: Volume Rational
  -- 473176473 % 16000000000000 m^3
  usFluidOunce :: (Fractional a) => Unit 'NonMetric DVolume a
  usFluidOunce = mkUnitQ (ucum "[foz_us]" "fl oz" "fluid ounce") (1 Prelude./ 16) $ usPint -- sic, does not match factor used in imperial system
  
  -- | One Ångström is 1/10 'nano' 'meter'.
  --
  -- See <https://en.wikipedia.org/wiki/%C3%85ngstr%C3%B6m here> for further information.
  --
  -- >>> 1 *~ angstrom
  -- 1.0e-10 m
  --
  -- >>> 1 *~ angstrom :: Length Rational
  -- 1 % 10000000000 m
  angstrom :: (Fractional a) => Unit 'NonMetric DLength a
  angstrom = mkUnitQ (ucum "Ao" "Å" "Ångström") 0.1 $ nano meter
  
  -- | One Gauss is 1/10000 'tesla'.
  --
  -- See <https://en.wikipedia.org/wiki/Gauss_%28unit%29 here> for further information.
  --
  -- >>> 1 *~ gauss
  -- 1.0e-4 kg s^-2 A^-1
  --
  -- >>> 1 *~ gauss :: MagneticFluxDensity Rational
  -- 1 % 10000 kg s^-2 A^-1
  gauss :: (Fractional a) => Unit 'NonMetric DMagneticFluxDensity a
  gauss = mkUnitQ (ucum "G" "G" "Gauss") 1e-4 $ tesla
  