7 ms·
It's not common to close that brace when writing math. (I've not seen it.)
by yig 4y ago
It's not common to close that brace when writing math. (I've not seen it.)
- layer8 4y agoAh, right, I see now what is is, I was confused. Another thing I find confusing are the braces around ℤ × ℤ. They seem to be unnecessary (it wouldn’t make much sense for ∈ to have higher precedence than ×), and/or would imply a singleton set containing the set ℤ × ℤ as its only element.
- jamessb 4y agoI wonder whether adding a brace for each row would clarify the notation, by more closely resembling a single multi-line brace: A_ij = { 1 if (i,j) ∈ E { 0 otherwise where A ∈ ℝ^(n × n) E ∈ { ℤ × ℤ } n ∈ ℤ
- xigoi 4y agoIf they want it to look like actual math notation, they might as well: A_ij = ⎰ 1 if (i,j) ∈ E ⎱ 0 otherwise where A ∈ ℝ^(n × n) E ∈ { ℤ × ℤ } n ∈ ℤ
- yig 4y agoUnicode actually has semantic symbols that could be used for a nicer 2D monospaced layout here, such as ⎧ ⎪ ⎨ ⎩ ( (LEFT CURLY BRACKET UPPER HOOK, MIDDLE PIECE, LOWER HOOK, and CURLY BRACKET EXTENSION). With more conditional rows, you could use these. One downside is that you would have to do a 2D parse, since the = wouldn't be on the first line. We've been loath to go there. It also seems painful as a user to have to type all the right bracket symbols in all the right places. We do support the Unicode ⎡|⎦ symbols for matrices. The grammar is that a matrix starts with either [ or ⎡ and ends with either ] or ⎦. Rows can be optionally surrounded by |. I find this too cumbersome to use myself.
- yig 4y agoI like this. I created a GitHub issue: https://github.com/iheartla/iheartla/issues/138 https://github.com/iheartla/iheartla/issues/138
- xeonmc 4y agoWhy not use the haskell guard syntax? A_ij = | 1 if (i,j) ∈ E | 0 otherwise where A ∈ ℝ^(n × n) E ∈ { ℤ × ℤ } n ∈ ℤ
- yig 4y agoI (speaking as a designer of I Heart LA empathizing with a user) wouldn't have thought to use that character as an approximation of {.