# Lambda

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Lambda (; [1] uppercase Λ, lowercase λ; Greek : λάμ(β)δα, lám(b)da) is the 11th letter of the Greek alphabet, representing the voiced alveolar lateral approximant IPA: . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoenician Lamed . Lambda gave rise to the Latin L and the Cyrillic El (Л). The ancient grammarians and dramatists give evidence to the pronunciation as (λάβδα) in Classical Greek times. [2] In Modern Greek, the name of the letter, Λάμδα, is pronounced .

## Contents

In early Greek alphabets, the shape and orientation of lambda varied. [3] Most variants consisted of two straight strokes, one longer than the other, connected at their ends. The angle might be in the upper-left, lower-left ("Western" alphabets) or top ("Eastern" alphabets). Other variants had a vertical line with a horizontal or sloped stroke running to the right. With the general adoption of the Ionic alphabet, Greek settled on an angle at the top; the Romans put the angle at the lower-left.

The HTML 4 character entity references for the Greek capital and small letter lambda are &#923; and &#955; respectively. [4] The Unicode code points for lambda are U+039B and U+03BB.

## Symbol

### Upper-case letter Λ

Examples of the symbolic use of uppercase lambda include:

### Lower-case letter λ

Examples of the symbolic use of lowercase lambda include:

### Litra symbol

The Roman libra and Byzantine lítra (λίτρα), which served as both the pound mass unit and liter volume unit, were abbreviated in Greek using lambda with modified forms of the iota subscript (as λͅ). These are variously encoded in Unicode. The Ancient Greek Numbers Unicode block includes 10183 GREEK LITRA SIGN (𐆃) as well as 𐅢, which is described as 10162 GREEK ACROPHONIC HERMIONIAN TEN [16] but was much more common as a form of the litra sign. A variant of the sign can be formed from 0338 COMBINING LONG SOLIDUS OVERLAY and either 039B GREEK CAPITAL LETTER LAMDA (Λ̸) or 03BB GREEK SMALL LETTER LAMDA (λ̸). [17]

## Character encodings

Unicode uses the (Modern Greek-based) spelling "lamda" in character names, instead of "lambda", due to "the pre-existing names in ISO 8859-7, as well as preferences expressed by the Greek National Body". [18]

• Greek Lambda / Coptic Laula
Character information
PreviewΛλ
Unicode nameGREEK CAPITAL LETTER LAMDAGREEK SMALL LETTER LAMDAGREEK LETTER SMALL CAPITAL LAMDACOPTIC CAPITAL LETTER LAULACOPTIC SMALL LETTER LAULA
Encodingsdecimalhexdechexdechexdechexdechex
Unicode 923U+039B955U+03BB7463U+1D2711414U+2C9611415U+2C97
UTF-8 206 155CE 9B206 187CE BB225 180 167E1 B4 A7226 178 150E2 B2 96226 178 151E2 B2 97
Numeric character reference &#923;&#x39B;&#955;&#x3BB;&#7463;&#x1D27;&#11414;&#x2C96;&#11415;&#x2C97;
Named character reference &Lambda;&lambda;
DOS Greek 1388A162A2
DOS Greek-2 182B6229E5
Windows-1253 203CB235EB
TeX \Lambda\lambda
• Mathematical Lambda
Character information
Preview𝚲𝛌𝛬𝜆𝜦𝝀
Unicode nameMATHEMATICAL BOLD
CAPITAL LAMDA
MATHEMATICAL BOLD
SMALL LAMDA
MATHEMATICAL ITALIC
CAPITAL LAMDA
MATHEMATICAL ITALIC
SMALL LAMDA
MATHEMATICAL BOLD ITALIC
CAPITAL LAMDA
MATHEMATICAL BOLD ITALIC
SMALL LAMDA
Encodingsdecimalhexdechexdechexdechexdechexdechex
Unicode 120498U+1D6B2120524U+1D6CC120556U+1D6EC120582U+1D706120614U+1D726120640U+1D740
UTF-8 240 157 154 178F0 9D 9A B2240 157 155 140F0 9D 9B 8C240 157 155 172F0 9D 9B AC240 157 156 134F0 9D 9C 86240 157 156 166F0 9D 9C A6240 157 157 128F0 9D 9D 80
UTF-16 55349 57010D835 DEB255349 57036D835 DECC55349 57068D835 DEEC55349 57094D835 DF0655349 57126D835 DF2655349 57152D835 DF40
Numeric character reference &#120498;&#x1D6B2;&#120524;&#x1D6CC;&#120556;&#x1D6EC;&#120582;&#x1D706;&#120614;&#x1D726;&#120640;&#x1D740;
Character information
Preview𝝠𝝺𝞚𝞴
Unicode nameMATHEMATICAL SANS-SERIF
BOLD CAPITAL LAMDA
MATHEMATICAL SANS-SERIF
BOLD SMALL LAMDA
MATHEMATICAL SANS-SERIF
BOLD ITALIC CAPITAL LAMDA
MATHEMATICAL SANS-SERIF
BOLD ITALIC SMALL LAMDA
Encodingsdecimalhexdechexdechexdechex
Unicode 120672U+1D760120698U+1D77A120730U+1D79A120756U+1D7B4
UTF-8 240 157 157 160F0 9D 9D A0240 157 157 186F0 9D 9D BA240 157 158 154F0 9D 9E 9A240 157 158 180F0 9D 9E B4
UTF-16 55349 57184D835 DF6055349 57210D835 DF7A55349 57242D835 DF9A55349 57268D835 DFB4
Numeric character reference &#120672;&#x1D760;&#120698;&#x1D77A;&#120730;&#x1D79A;&#120756;&#x1D7B4;

These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.

## Related Research Articles

Epsilon is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel IPA: [e]. In the system of Greek numerals it also has the value five. It was derived from the Phoenician letter He . Letters that arose from epsilon include the Roman E, Ë and Ɛ, and Cyrillic Е, È, Ё, Є and Э.

Eta is the seventh letter of the Greek alphabet, representing the close front unrounded vowel IPA: [i]. Originally denoting the voiceless glottal fricative IPA: [h] in most dialects, its sound value in the classical Attic dialect of Ancient Greek was a long open-mid front unrounded vowel IPA: [ɛː], raised to IPA: [i] in hellenistic Greek, a process known as iotacism or itacism.

Gamma is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop IPA: [ɡ]. In Modern Greek, this letter represents either a voiced velar fricative IPA: [ɣ] or a voiced palatal fricative IPA: [ʝ].

Iota is the ninth letter of the Greek alphabet. It was derived from the Phoenician letter Yodh. Letters that arose from this letter include the Latin I and J, the Cyrillic І, Yi, and Je, and iotated letters. In the system of Greek numerals, iota has a value of 10.

Omega is the 24th and last letter in the Greek alphabet. In the Greek numeric system/isopsephy (gematria), it has a value of 800. The word literally means "great O", as opposed to omicron, which means "little O".

Chi is the 22nd letter of the Greek alphabet.

Phi is the 21st letter of the Greek alphabet.

Tau is the 19th letter of the Greek alphabet. In the system of Greek numerals, it has a value of 300.

Pi is the sixteenth letter of the Greek alphabet, representing the sound. In the system of Greek numerals it has a value of 80. It was derived from the Phoenician letter Pe. Letters that arose from pi include Latin P, Cyrillic Pe, Coptic pi, and Gothic pairthra (𐍀).

Xi is the name of the 14th letter of the Greek alphabet. It is pronounced [ksi] in Modern Greek, and generally or in English. In the system of Greek numerals, it has a value of 60. Xi was derived from the Phoenician letter samekh .

Mu is the 12th letter of the Greek alphabet, representing the voiced bilabial nasal IPA: [m]. In the system of Greek numerals it has a value of 40. Mu was derived from the Egyptian hieroglyphic symbol for water, which had been simplified by the Phoenicians and named after their word for water, to become 𐤌 (mem). Letters that derive from mu include the Roman M and the Cyrillic М.

Theta is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth . In the system of Greek numerals, it has a value of 9.

Sigma is the eighteenth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 200. In general mathematics, uppercase Σ is used as an operator for summation. When used at the end of a letter-case word, the final form (ς) is used. In Ὀδυσσεύς (Odysseus), for example, the two lowercase sigmas (σ) in the center of the name are distinct from the word-final sigma (ς) at the end. The Latin letter S derives from sigma while the Cyrillic letter Es derives from a lunate form of this letter.

Kappa is the 10th letter of the Greek alphabet, used to represent the voiceless velar plosive IPA: [k] sound in Ancient and Modern Greek. In the system of Greek numerals, has a value of 20. It was derived from the Phoenician letter kaph . Letters that arose from kappa include the Roman K and Cyrillic К.

Rho is the 17th letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician letter res . Its uppercase form uses the same glyph, Ρ, as the distinct Latin letter P; the two letters have different Unicode encodings.

Psi is the 23rd letter of the Greek alphabet and is associated with a numeric value of 700. In both Classical and Modern Greek, the letter indicates the combination.

The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BCE. It is derived from the earlier Phoenician alphabet, and was the earliest known alphabetic script to have distinct letters for vowels as well as consonants. In Archaic and early Classical times, the Greek alphabet existed in many local variants, but, by the end of the 4th century BCE, the Euclidean alphabet, with 24 letters, ordered from alpha to omega, had become standard and it is this version that is still used for Greek writing today.

Greek letters are used in mathematics, science, engineering, and other areas where mathematical notation is used as symbols for constants, special functions, and also conventionally for variables representing certain quantities. In these contexts, the capital letters and the small letters represent distinct and unrelated entities. Those Greek letters which have the same form as Latin letters are rarely used: capital A, B, E, Z, H, I, K, M, N, O, P, T, Y, X. Small ι, ο and υ are also rarely used, since they closely resemble the Latin letters i, o and u. Sometimes font variants of Greek letters are used as distinct symbols in mathematics, in particular for ε/ϵ and π/ϖ. The archaic letter digamma (Ϝ/ϝ/ϛ) is sometimes used.

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L, or l, is the twelfth letter of the modern English alphabet and the ISO basic Latin alphabet. Its name in English is el, plural els.

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