# Therefore sign

Therefore sign
Punctuation
apostrophe  '
brackets [ ]  ( )  { }  ⟨ ⟩
colon :
comma ,  ،
dash ‒  –  —  ―
ellipsis  ...  . . .
exclamation mark !
full stop, period .
guillemets ‹ ›  « »
hyphen
hyphen-minus -
question mark ?
quotation marks ‘ ’  “ ”  ' '  " "
semicolon ;
slash, stroke, solidus /
Word dividers
interpunct ·
space
General typography
ampersand &
asterisk *
at sign @
backslash \
basis point
bullet
caret ^
dagger † ‡ ⹋
degree °
ditto mark ” 〃
equals sign =
inverted exclamation mark ¡
inverted question mark ¿
komejirushi, kome, reference mark
multiplication sign ×
number sign, pound, hash #
numero sign
obelus ÷
ordinal indicator º ª
percent, per mil % ‰
pilcrow
plus, minus + −
plus-minus, minus-plus ± ∓
prime
section sign §
tilde ~
underscore, understrike _
vertical bar, pipe, broken bar |    ¦
Intellectual property
copyleft 🄯
service mark
Currency
currency sign ¤

؋฿¢\$֏ƒ£元 圆 圓 ¥

Uncommon typography
asterism
fleuron, hedera
index, fist
interrobang
irony punctuation
lozenge
tie
Related
In other scripts

In logical argument and mathematical proof, the therefore sign (∴) is generally used before a logical consequence, such as the conclusion of a syllogism. The symbol consists of three dots placed in an upright triangle and is read therefore. It is encoded at U+2234 THEREFORE (HTML `&#8756;` · `&there4;`).[1] While it is not generally used in formal writing, it is used in mathematics and shorthand. It is complementary to U+2235 BECAUSE (HTML `&#8757;`).

## History

According to Cajori, A History of Mathematical Notations, Johann Rahn used both the therefore and because signs to mean "therefore"; in the German edition of Teutsche Algebra (1659) the therefore sign was prevalent with the modern meaning, but in the 1668 English edition Rahn used the because sign more often to mean "therefore".[2] Other authors in the 18th century also used three dots in a triangle shape to signify "therefore", but as with Rahn, there wasn't much in the way of consistency as to how the triangle was oriented; because with its current meaning appears to have originated in the 19th century. In this[which?] century, the three-dot notation for therefore became very rare in continental Europe, but it remains popular in the British Isles.[3]

## Example of use

Used in a syllogism:

All gods are immortal.
Zeus is a god.
∴ Zeus is immortal.
x + 1 = 10
∴ x = 9

## Related signs

The inverted form ∵, known as the because sign, is sometimes used as a shorthand form of "because". This is Unicode character U+2235 BECAUSE.

The therefore sign is sometimes used as a substitute for an asterism ⁂.

In meteorology, the therefore sign is used to indicate moderate rain on a station model; the asterism indicates moderate snow.[4][5]

To denote logical implication or entailment, various signs are used in mathematical logic: →, ⇒, ⊃, ⊢, ⊨. These symbols are then part of a mathematical formula and are not considered to be punctuation. In contrast, the therefore sign is traditionally used as a punctuation mark and does not form part of a logical formula.[6]

The graphically identical sign ∴ serves as a Japanese map symbol on the maps of the Geographical Survey Institute of Japan, indicating a tea plantation. On some maps the sign appears with thicker dots, used to signal the presence of a national monument or ruins.

The character ஃ in the Tamil script represents the āytam, a special sound of the Tamil language.

In Norwegian and Danish, a similar symbol is used as an explanatory symbol (forklaringstegnet). It can be typeset using the open o followed by a colon, thus: ɔ:. It is used for the meaning "namely", "id est", "scilicet" or similar[7].

## Use in Freemasonry

A diploma from the Masonic Grande Loge de France showing the symbol as a substitute for the dot of abbreviation

In Masonic traditions the symbol is used for abbreviation, instead of the usual period, essentially an initial or monogram continuing the meaning of "therefore", "standing for", i.e. "thus" (Latin: sic). For example, "R∴W∴ John Smith" is an abbreviation for "Right Worshipful John Smith" (the term Right Worshipful is an archaic title, just as "Land Lord" is and indicates that Brother Smith is a Grand Lodge officer).[8]

Because the symbol is not usually available on keyboards and within fonts, and to prevent compatibility issues, users have substituted a colon followed by a period (":.") to represent it.[citation needed]