Claudà tors i agrupament
The quotation marks in the examples are used to emphasize text and do not belong to the content of the formulas and commands.
Quan escriviu fórmules d'exemple a la finestra d'ordes, tingueu en compte que sovint necessitareu incloure espais per obtindre l'estructura correcta.
Braces "{}" are used to group expressions together to form one new expression. For example, sqrt {x * y} is the square root of the entire product x*y, while sqrt x * y is the square root of x multiplied by y. Braces do not require an extra space.
Set brackets were previously inserted in the Elements pane or directly in the Commands window as "left lbrace <?> right rbrace". Now, a left and a right set bracket can also be inserted using "lbrace" and "rbrace", with or without wildcards.
There are a total of eight (8) different types of brackets available. The "ceil" and "floor" brackets are often used for rounding up or down the argument to the next integer: lceil -3.7 rceil = -3 or lfloor -3.7 rfloor = -4.
Operator brackets, also known as Bra-kets (angle brackets with a vertical line in between), are common in Physics notation: langle a mline b rangle or langle a mline b mline c over d mline e rangle. The height and positioning of the vertical lines always corresponds exactly to the enclosing brackets.
Tots els tipus de claudà tors s'han d'utilitzar de dos en dos i tenen una sèrie de caracterÃstiques comunes:
Tots els tipus de claudà tors tenen la mateixa funció d'agrupament descrita per a les claus "{}".
Tots els tipus de claudà tors, inclosos els visibles, permeten la definició de grups buits; és a dir, que poden incloure expressions buides.
Brackets do not adjust their size to the enclosed expression. For example, if you want ( a over b ) with a bracket size adjusted to a and b you must insert "left" and "right". Entering left(a over b right) produces appropriate sizing. If, however, the brackets themselves are part of the expression whose size is changed, they are included the size change: size 3(a over b) and size 12(a over b). The sizing of the bracket-to-expression ratio does not change in any way.
Atès que "left" i "right" asseguren l'assignació única dels claudà tors, podeu utilitzar cada claudà tor únic com a argument per a estes dues ordes, i fins i tot podeu ubicar claudà tors drets a l'esquerra o claudà tors esquerres a la dreta. D'altra banda, podeu utilitzar el qualificador "none" en lloc d'un claudà tor. Amb esta orde no es mostrarà cap claudà tor ni es reservarà cap espai per al claudà tor, i podreu crear les expressions següents:
-
left lbrace x right none
-
left [ x right )
-
left ] x right [
-
left rangle x right lfloor
S'apliquen les mateixes regles per a les ordes "left" i "right" referents als altres tipus de claudà tors: també funcionen com a constructors de grups i poden incloure expressions buides.
Les fórmules matemà tiques sovint contenen combinacions de claudà tors desaparellats, claudà tors únics i claudà tors esquerres i drets reposicionats. Si introduïu la fórmula següent es generarà un error:
-
[2, 3) - right open interval
Using "left" and "right" makes the above expression valid in LibreOffice Math: left [2, 3 right ). However, the brackets do not have any fixed size because they adjust to the argument. Setting a single bracket is a bit cumbersome. Therefore, there you can display single brackets with a fixed size by placing a "\" (backslash) in front of normal brackets. These brackets then act like any other symbol and no longer have the special functionality of brackets; that is they do not work as group builders and their orientation corresponds to that of other symbols. See size *2 \langle x \rangle and size *2 langle x rangle.
Visió general completa:
-
\{ or \lbrace, \} or \rbrace
-
\(, \)
-
\[, \]
-
\langle, \rangle
-
\lceil, \rceil
-
\lfloor, \rfloor
-
\lline, \rline
-
\ldline, \rdline
Si utilitzeu estes ordes podreu construir sense problemes intervals com l'anterior al LibreOffice Math: \[2", "3\) o "\]2", "3\[ (atenció, les cometes de l'exemple formen part de l'entrada).
Tingueu en compte que les cometes són obligatòries i que cal introduir-les amb la combinació de tecles Maj+2, és a dir, que no poden ser cometes tipogrà fiques. En general, els signes de puntuació (com la coma en este cas) es defineixen com a text. Malgrat que també podeu escriure "\[2,~3\)", és preferible l'opció anterior. En l'exemple anterior, el concepte "mida fixa" sempre descriu una mida de claudà tor que depèn de la mida de lletra utilitzada.
Nesting groups within each other is relatively problem-free. In the formula hat "{a + b}" the "hat" is displayed simply over the center of "{a + b}". Also, color red lceil a rceil and grave hat langle x * y rangle work as expected. The result of the latter can be compared to grave {hat langle x * y rangle}. These attributes do not compete, but rather can be combined.
This differs slightly for competing or mutually influencing attributes. This is often the case with font attributes. For example, which color does the b have in color yellow color red (a + color green b), or which size does it have in size *4 (a + size /2 b)? Given a base size of 12, does it have the size 48, 6 or even 24 (which could be seen as a combination)? The following are basic resolution rules, which will be followed consistently in the future. In general, the rules apply to all group operations. This only has a visible effect on the font attributes, like "bold", "ital", "phantom", "size", "color" and "font":
-
Group operations in sequence are treated as if every single operation is enclosed by braces. They are nested, and in every level there can be no more than one operation. Here is an example of a formula with many group operations:
size 12 color red font sans size -5 (a + size 8 b)" like "{size 12{color red{font sans{size -5 (a + {size 8 b})}}}}.
-
Esta fórmula d'exemple s'interpreta d'esquerra a dreta. Les operacions només afecten el seu grup (o expressió) corresponent. Les operacions de la dreta "reemplacen" les seues predecessores o s'hi "combinen".
-
A group operation does not have any effect on higher-level operations but rather affects only lower-level groups and expressions, including their brackets and super-/subscripts. For example,
a + size *2 (b * size -8 c_1)^2
Tant "color ..." com "font ..." i "size n" (en què n és un decimal) reemplacen qualsevol operació anterior del mateix tipus
Per a "size +n", "size -n", "size *n" i "size /n" es combinen els efectes de les operacions.
size *2 size -5 a would be double the starting size minus 5
font sans ( a + font serif b)
size *2 ( a + size /2 b )
To change the size of a formula, use "size +" or -,*,/. Do not use "size n". These can easily be used in any context. This enables you to copy to other areas by using Copy and Paste, and the result remains the same. Furthermore, such expressions survive a change of base size in the menu better than when using "size n". If you use only size * and size / (for example, size *1.24 a or size /0.86 a) the proportions remain intact.
Exemples (amb una mida base de 12 i 50% per als Ãndexs):
Exactly identical proportions with size 18 a_n and size *1.5 a_n.
This differs in different contexts: x^{size 18 a_n} and x^{size *1.5 a_n}
Examples with size +n for a comparison. They look identical:
a_{size 8 n}
a_{size +2 n}
a_{size *1.333 n}
Tanmateix, els exemples següents no són idèntics:
x^{a_{size 8 n}}
x^{a_{size +2 n}}
x^{a_{size *1.333 n}}
All n here have different sizes. The size 1.333 results from 8/6, the desired size divided by the default index size 6. (Index size 50% with a base size of 12)