Day 99/100: The Therefore Sign (∴) In 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'. While it is not generally used in formal writing, it is used in mathematics and shorthand. It is complementary to '∵', meaning because. Example use in a syllogism: All gods are immortal. Zeus is a god. ∴ Zeus is immortal. Or: x + 1 = 6 ∴ x = 5 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. [Three drops of nail varnish on card] #100daysofthepunctuationproject #100days #the100dayproject #gm100dayproject #therefore #thereforesign #punctuation #punctuationsymbols #punctuationdesign #punctuationlibrary #punctuationmarks #shorthand #shorthandsymbols #mathematicalsymbols #maths #syllogism #dots #triangle #uprighttriangle #nailvarnish #nailvarnishdots #spots