A unit of volume containing 8 Imperial pints.

One eighth of an Imperial gallon, containing 20 fluid ounces.

A unit of volume; the Imperial and United States measures differ. An Imperial fluid ounce contains 8 fluid drachms.

The British pharmaceutical volume of 60 minims; 8 make an Imperial fluid ounce.

A unit of volume equal to one cubic decimetre.

One thousandth of a litre, equal to one cubic centimetre.

A unit of mass is a reference for expressing mass. The SI base unit is the kilogram; the gram is $10^{-3}\mathrm{kg}$. A unit of mass differs from a unit of force: a balance may infer mass from a gravitational force, but a newton measures force and is not another name for a kilogram.

In a weighing experiment the relation $F=mg$ connects the two, with local gravitational acceleration $g$. An instrument calibrated to display mass therefore incorporates a reference or an assumed local $g$. Moving a force-sensing instrument to a different gravitational environment can change that inference even though the specimen's mass is unchanged.^[ref]

A unit of volume is a reference for expressing a three-dimensional volume. In the International System of Units its coherent form is the cubic metre, ${\mathrm{m}}^3$. A litre is $10^{-3}{\mathrm{m}}^3$ and a millilitre is $10^{-6}{\mathrm{m}}^3$.

Length conversions must be cubed: because $1\mathrm{cm}=10^{-2}\mathrm{m}$, one cubic centimetre equals $10^{-6}{\mathrm{m}}^3$, rather than $10^{-2}{\mathrm{m}}^3$. This accounting matters when a measured mass and volume determine a mass density, or when a number density is converted between laboratory and SI conventions.^[ref]

Compression ultrasonography combines ultrasonography with observation of how a structure deforms under an applied load. For a vein, the image records whether the opposing walls approach each other during compression. A segment that fails to compress can provide evidence of an obstructing thrombus; the useful measurement is the dynamic mechanical response as well as its visual appearance.^[ref]

Interpretation depends on adequate visualization and loading: an incomplete view or ineffective compression does not establish the same physical observation as a properly imaged noncompressible segment. This illustrates a general measurement principle: the input perturbation and the object's response both belong to the experiment.

Doppler ultrasonography applies Doppler ultrasound to motion within the body, especially flowing blood. Moving scatterers change the returned frequency or phase; the shift measures a component of velocity along the acoustic geometry. Combining that information with ultrasonography locates motion relative to the imaged structures.^[ref]

A color map assigns a display color to a measured flow quantity under a chosen sign convention. It therefore represents an inferred motion, rather than the literal optical color of the blood. Estimating a speed requires the beam-to-flow angle and the assumptions behind the Doppler ultrasound measurement; a small shift can reflect a nearly transverse flow as well as a small speed.

Transvaginal ultrasound is pelvic ultrasonography with an internal probe positioned in the vagina, close to pelvic structures such as the uterus and ovaries. This changes the imaging geometry and the intervening acoustic path. The measured signal is still an ultrasound echo; the probe's position supplies access to structures that can be harder to view along an external abdominal path.^[ref]

Use of ultrasonography to examine the urinary bladder, including assessment of its distension in suspected urinary retention.

A type whose values are described by named data constructors with specified fields. For example, data Tree a = One a | Two (Tree a) (Tree a) describes a leaf-labelled binary tree. Its two alternatives are distinguished by pattern matching; the recursive fields give a recursive type.

A type-level constructor accepting the number and kinds of type arguments specified by its kind of a type. For example, Tree accepts one ordinary type and produces Tree a; it has kind * -> *. A data constructor such as One operates at the value level instead. The two levels can use separate namespaces in a programming language.

A classification of type-level expressions. In the traditional Haskell notation, ordinary types have kind *, while a unary type constructor such as Tree has kind * -> *. Applying it to a suitable type argument produces an ordinary type. This distinguishes the type-level application from applying a value with a function type.

An operation checking that a value has a requested runtime extension type and exposing the fields of that type. In Oberon, a pointer guard such as p(RealTail) permits a pointer to a base record to access the real-valued field of an appropriate record extension. Failure of the dynamic type check is a runtime error, so a representation invariant should establish that guarded values have the requested extension before the operation is used.

A classification of program values together with the operations permitted on them. An algebraic data type describes values by data constructors; a function type describes acceptable arguments and produced results.

A data type without universally quantified type variables. During Hindley-Milner type inference, every use of a lambda-bound parameter shares one type, even if that type initially contains unknowns to be unified. In contrast, suitable let-bound definitions may admit let polymorphism.

Maintain consecutive regions less than a saved pivot value, equal to it, unclassified, and greater than it. Compare the first unclassified entry: move a smaller one into the lower region, advance over an equal one, or exchange a greater one with the final unclassified entry. In the last case the incoming entry still needs classification. Each step shortens the unclassified interval by one. The final equality interval is nonempty when the pivot was selected from the input; Quickselect can discard that entire interval when searching another rank. Saving the value avoids accidentally comparing against a pivot index whose contents have moved.

Historical pharmaceutical preparation; its composition and clinical use must be identified by edition. ^[ref]