Midline Three Dots Symbol ⋯

Use ⋯ when centered horizontal omission or continuation is required in mathematical layout, including row or column elision conventions. Use … for ordinary prose omission or trailing-off punctuation unless a style guide says otherwise. The three dots symbol covered here is ⋯, Unicode U+22EF MIDLINE HORIZONTAL ELLIPSIS. Its dots sit on the mathematical center line, which separates it from U+2026 … HORIZONTAL ELLIPSIS used mainly in prose. Unicode describes the midline ellipsis as a mathematical symbol and includes it with special ellipsis characters used for omission in matrix notation. In formulas and matrices, ⋯ can indicate that terms or columns continue according to a pattern already established by the surrounding expression. For example, x₁, x₂, ⋯, xₙ shows a centered continuation between indexed terms. The symbol does not define the missing pattern by itself; the variables, indices, and explanation must make the continuation clear. Vertical omission uses ⋮, and diagonal matrix omission may use characters such as ⋱. These are separate code points and should not be substituted merely because all of them contain dots. Saved test strings for Midline Three Dots Symbol: a₁ + a₂ + ⋯ + aₙ; [1 2 ⋯ n]; x₁, x₂, ⋯, xₙ; Matrix row: a₁₁ a₁₂ ⋯ a₁ₙ; Centered continuation ⋯. Rules retained for Midline Three Dots Symbol: Use ⋯ for a centered mathematical ellipsis and … for the ordinary horizontal ellipsis in prose. Keep ⋯ as one character, U+22EF, rather than three full stops. In a matrix or displayed equation, let the math layout engine align the symbol on the mathematical center line. Use ⋮ for vertical elision and the appropriate diagonal ellipsis when a matrix omits diagonal entries. The Midline Three Dots Symbol error check covers: Using … U+2026 when mathematical midline placement is required. Typing three periods ... and assuming they are the same character as ⋯. Using ⋯ as ordinary prose punctuation without a mathematical or technical reason. Confusing ⋯ with ⋮, the vertical ellipsis used for vertical omission. Comparison set for Midline Three Dots Symbol: … means Horizontal Ellipsis—prose punctuation; ⋮ means Vertical Ellipsis—vertical matrix elision; ⋱ means Down Right Diagonal Ellipsis—diagonal matrix elision. For Midline Three Dots Symbol, literal UTF-8 ⋯, decimal ⋯, hexadecimal ⋯, and CSS 22EF all need to preserve U+22EF; verify the result at /symbols/3-dot/ in the target font.